Remove build --stage 0 from CI scripts

Author: Kobzol

src/ci/docker/host-x86_64/mingw-check-1/Dockerfile

@@ -46,7 +46,7 @@ COPY host-x86_64/mingw-check-1/validate-error-codes.sh /scripts/
 # We also skip the x86_64-unknown-linux-gnu target as it is well-tested by other jobs.
 ENV SCRIPT \
            /scripts/check-default-config-profiles.sh && \
-           python3 ../x.py build --stage 0 src/tools/build-manifest && \
+           python3 ../x.py build --stage 1 src/tools/build-manifest && \
            python3 ../x.py test --stage 0 src/tools/compiletest && \
            python3 ../x.py check compiletest --set build.compiletest-use-stage0-libtest=true && \
            python3 ../x.py check --stage 1 --target=i686-pc-windows-gnu --host=i686-pc-windows-gnu && \

src/ci/docker/scripts/rfl-build.sh

@@ -6,7 +6,7 @@ LINUX_VERSION=v6.16-rc1
 
 # Build rustc, rustdoc, cargo, clippy-driver and rustfmt
 ../x.py build --stage 2 library rustdoc clippy rustfmt
-../x.py build --stage 0 cargo
+../x.py build --stage 1 cargo
 
 BUILD_DIR=$(realpath ./build/x86_64-unknown-linux-gnu)