tensorflow-core: Remove build-dep on cython

[dannf]

tensorflow-core is the last remaining package that uses cython~0, so I checked to see if it was compatible with current cython. But, as far as I could tell, cython is simply never used.

To confirm, I did a build of tensorflow-core where I touched a reference file after the build-deps (including cython) had been installed and then, after each (sub-)package build, ran:

find $(apk info -L cython | grep -v ^cython | grep -v '^$' | sed 's/^/\//') -anewer /tmp/reference | sed 's/^/DANNF: /'

I found no 'DANNF:' lines in the output. This tells me that nothing in the build accessed any files provided by the cython package.

See: #37272

[xnox]

Doesn't this causes to use precompiled cython files or download old cython?

But yes it would be great to get rid of old cython!!!!! Would want to double check this analysis when I am on my laptop.

[dannf]

I didn't see any references to cython in the logs, nor did I see any when I grep'd a local build log w/ bazel --subcommands:

$ sed 's/TF_SYSTEM_LIBS=boringssl,curl,cython,gif,icu,libjpeg_turbo,nasm,png,zlib//' < tensorflow+subcommands.log  | grep -i cython
2024/12/27 19:30:17 INFO     packages:     [alsa-lib=1.2.13-r0 apk-tools=2.14.4-r1 bash=5.2.37-r2 bazelisk-default=1.25.0-r0 bazelisk=1.25.0-r0 binutils=2.43.1-r2 brotli-dev=1.1.0-r4 brotli=1.1.0-r4 build-base=1-r8 busybox=1.37.0-r0 c-ares-dev=1.34.4-r0 c-ares=1.34.4-r0 ca-certificates-bundle=20241010-r2 ca-certificates=20241010-r2 clang-16-dev=16.0.6-r6 clang-16=16.0.6-r6 coreutils=9.5-r3 curl-dev=8.11.1-r0 cyrus-sasl=2.1.28-r5 cython-0=0.29.37.1-r2 e2fsprogs-dev=1.47.1-r1 e2fsprogs-libs=1.47.1-r1 fontconfig-config=2.15.0-r2 freetype=2.13.3-r0 gawk=5.3.1-r1 gcc-12-default=12.4.0-r7 gcc-12=12.4.0-r7 gdbm=1.24-r1 giflib-dev=5.2.2-r4 giflib=5.2.2-r4 git=2.47.1-r0 glib=2.83.2-r1 glibc-dev=2.40-r3 glibc-locale-posix=2.40-r3 glibc=2.40-r3 gmp=6.3.0-r2 hdf5-cpp=1.14.5-r0 hdf5-dev=1.14.5-r0 hdf5-fortran=1.14.5-r0 hdf5-hl-cpp=1.14.5-r0 hdf5-hl-fortran=1.14.5-r0 hdf5-hl=1.14.5-r0 hdf5=1.14.5-r0 heimdal-libs=7.8.0-r7 icu-data-full=75.1-r5 icu-dev=75.1-r5 icu-libs=75.1-r5 icu=75.1-r5 isl-dev=0.27-r0 isl=0.27-r0 java-cacerts=20240705-r0 java-common=0.1-r3 jitterentropy-library-dev=3.6.1-r0 jitterentropy-library=3.6.1-r0 keyutils-libs=1.6.3-r5 krb5-conf=1.0-r3 krb5-dev=1.21.3-r2 krb5-libs=1.21.3-r2 krb5-server-ldap=1.21.3-r2 lcms2=2.16-r3 ld-linux=2.40-r3 libLLVM-16=16.0.6-r3 libacl1=2.3.2-r4 libattr1=2.5.2-r4 libblkid=2.40.2-r1 libbrotlicommon1=1.1.0-r4 libbrotlidec1=1.1.0-r4 libbrotlienc1=1.1.0-r4 libbz2-1=1.0.8-r9 libclang-cpp-16=16.0.6-r6 libcom_err=1.47.1-r1 libcrypt1=2.40-r3 libcrypto3=3.4.0-r5 libcurl-openssl4=8.11.1-r0 libev=4.33-r6 libevent=2.1.12-r6 libexpat1=2.6.4-r0 libfdisk=2.40.2-r1 libffi=3.4.6-r5 libfontconfig1=2.15.0-r2 libgcc=14.2.0-r6 libgfortran=14.2.0-r6 libidn2=2.3.7-r3 libjpeg-turbo-dev=3.1.0-r0 libjpeg-turbo=3.1.0-r0 libldap=2.6.9-r0 liblzf=3.6-r1 libmount=2.40.2-r1 libnghttp2-14=1.64.0-r1 libpcre2-8-0=10.44-r2 libpng-dev=1.6.44-r3 libpng=1.6.44-r3 libpsl-dev=0.21.5-r4 libpsl=0.21.5-r4 libquadmath=14.2.0-r6 libsmartcols=2.40.2-r1 libssl3=3.4.0-r5 libstdc++-12-dev=12.4.0-r7 libstdc++-12=12.4.0-r7 libstdc++=14.2.0-r6 libsz=1.1.3-r1 libtasn1=4.19.0-r4 libunistring=1.3-r1 libuuid=2.40.2-r1 libverto-dev=0.3.2-r4 libverto-glib=0.3.2-r4 libverto-libev=0.3.2-r4 libverto-libevent=0.3.2-r4 libverto=0.3.2-r4 libx11=1.8.10-r0 libxau=1.0.12-r0 libxcb=1.17.0-r3 libxcrypt-dev=4.4.36-r8 libxcrypt=4.4.36-r8 libxdmcp=1.1.5-r4 libxext=1.3.6-r4 libxi=1.8.2-r1 libxml2=2.13.5-r0 libxrender=0.9.12-r0 libxtst=1.2.5-r1 libzstd1=1.5.6-r5 linux-headers=6.6.67-r0 llvm-lld-16-dev=16.0.6-r7 llvm-lld-16=16.0.6-r7 llvm16-dev=16.0.6-r3 llvm16=16.0.6-r3 make=4.4.1-r4 mpc-dev=1.3.1-r5 mpc=1.3.1-r5 mpdecimal=4.0.0-r3 mpfr=4.2.1-r5 ncurses-terminfo-base=6.5_p20241006-r4 ncurses=6.5_p20241006-r4 nghttp2-dev=1.64.0-r1 nghttp2=1.64.0-r1 nss-db=2.40-r3 nss-hesiod=2.40-r3 openblas=0.3.28-r1 openjdk-11-default-jdk=11.0.25-r2 openjdk-11-default-jvm=11.0.25-r2 openjdk-11-jre-base=11.0.25-r2 openjdk-11-jre=11.0.25-r2 openjdk-11=11.0.25-r2 openssf-compiler-options=20240627-r6 openssl-dev=3.4.0-r5 p11-kit-trust=0.25.5-r1 p11-kit=0.25.5-r1 patchelf=0.18.0-r1 perl=5.40.0-r3 pkgconf=2.3.0-r1 posix-cc-wrappers=1-r4 py3-pip-wheel=24.3.1-r1 py3-setuptools-wheel=75.6.0-r0 py3-supported-gpep517=16-r4 py3-supported-installer=0.7.0-r10 py3-supported-keras-applications=1.0.8-r3 py3-supported-keras-preprocessing=1.1.2-r4 py3-supported-packaging=24.2-r1 py3-supported-pybind11=2.13.6-r3 py3-supported-requests=2.32.3-r4 py3-supported-setuptools=75.6.0-r1 py3.10-certifi=2024.12.14-r0 py3.10-charset-normalizer=3.4.1-r0 py3.10-gpep517=16-r4 py3.10-h5py=3.12.1-r3 py3.10-idna=3.10-r3 py3.10-installer=0.7.0-r10 py3.10-keras-applications=1.0.8-r3 py3.10-keras-preprocessing=1.1.2-r4 py3.10-numpy=1.26.4-r7 py3.10-packaging=24.2-r1 py3.10-pybind11=2.13.6-r1 py3.10-pyparsing=3.2.0-r2 py3.10-requests=2.32.3-r4 py3.10-setuptools=75.6.0-r1 py3.10-six=1.17.0-r1 py3.10-tomli=2.2.1-r1 py3.10-urllib3=2.3.0-r0 py3.11-certifi=2024.12.14-r0 py3.11-charset-normalizer=3.4.1-r0 py3.11-gpep517=16-r4 py3.11-h5py=3.12.1-r3 py3.11-idna=3.10-r3 py3.11-installer=0.7.0-r10 py3.11-keras-applications=1.0.8-r3 py3.11-keras-preprocessing=1.1.2-r4 py3.11-numpy=1.26.4-r7 py3.11-packaging=24.2-r1 py3.11-pybind11=2.13.6-r1 py3.11-pyparsing=3.2.0-r2 py3.11-requests=2.32.3-r4 py3.11-setuptools=75.6.0-r1 py3.11-six=1.17.0-r1 py3.11-tomli=2.2.1-r0 py3.11-urllib3=2.3.0-r0 py3.12-certifi=2024.12.14-r0 py3.12-charset-normalizer=3.4.1-r0 py3.12-gpep517=16-r4 py3.12-h5py=3.12.1-r3 py3.12-idna=3.10-r3 py3.12-installer=0.7.0-r9 py3.12-keras-applications=1.0.8-r3 py3.12-keras-preprocessing=1.1.2-r3 py3.12-numpy=1.26.4-r7 py3.12-packaging=24.2-r1 py3.12-pybind11=2.13.6-r1 py3.12-pyparsing=3.2.0-r2 py3.12-requests=2.32.3-r4 py3.12-setuptools=75.6.0-r1 py3.12-six=1.17.0-r1 py3.12-tomli=2.2.1-r1 py3.12-urllib3=2.3.0-r0 py3.13-certifi=2024.12.14-r0 py3.13-charset-normalizer=3.4.1-r0 py3.13-gpep517=16-r4 py3.13-h5py=3.12.1-r3 py3.13-idna=3.10-r3 py3.13-installer=0.7.0-r10 py3.13-keras-applications=1.0.8-r3 py3.13-keras-preprocessing=1.1.2-r4 py3.13-numpy=1.26.4-r7 py3.13-packaging=24.2-r1 py3.13-pybind11=2.13.6-r3 py3.13-pyparsing=3.2.0-r2 py3.13-requests=2.32.3-r4 py3.13-setuptools=75.6.0-r1 py3.13-six=1.17.0-r1 py3.13-tomli=2.2.1-r1 py3.13-urllib3=2.3.0-r0 py3.13-wheel-bin=0.45.1-r1 py3.13-wheel=0.45.1-r1 python-3.10-base=3.10.16-r0 python-3.11-base=3.11.11-r0 python-3.12-base=3.12.8-r2 python-3.13-base-dev=3.13.1-r4 python-3.13-base=3.13.1-r4 python-3.13-dev=3.13.1-r4 python-3.13=3.13.1-r4 readline=8.2.13-r1 scanelf=1.3.8-r1 sqlite-dev=3.47.2-r0 sqlite-libs=3.47.2-r0 sqlite=3.47.2-r0 ttf-dejavu=2.37-r3 util-linux-dev=2.40.2-r1 util-linux=2.40.2-r1 wolfi-base=1-r6 wolfi-baselayout=20230201-r15 wolfi-keys=1-r8 xz=5.6.3-r2 zlib-dev=1.3.1-r4 zlib=1.3.1-r4]
2024/12/27 19:30:20 INFO installing cython-0 (0.29.37.1-r2)

Here's that full build log:
tensorflow+subcommands.log.gz

Note that the version of cython this build would download, if needed, is 3.0.3:

tensorflow/workspace2.bzl:        urls = tf_mirror_urls("https://github.com/cython/cython/archive/3.0.3.tar.gz"),
third_party/xla/third_party/tsl/workspace2.bzl:        urls = tf_mirror_urls("https://github.com/cython/cython/archive/3.0.3.tar.gz"),

So a more cautious approach would be to leave the build-dep in place, but just drop the ~0.