Patch pyenv-build to not upgrade conda

When installing miniconda3, `pyenv-build` calls:

  conda install --yes pip

which automatically updates conda to its latest version and making us lossing
our pinned version.

This commit adds a patch to keep installing pip after conda install, but pinning
conda to the current version to avoid upgrading it automatically.

See pyenv/pyenv#2070

scripts/compile_version_upload_s3.sh

@@ -44,13 +44,24 @@ OS="ubuntu-20.04"
 TOOL=$1
 VERSION=$2
 
+# https://stackoverflow.com/questions/59895/how-can-i-get-the-source-directory-of-a-bash-script-from-within-the-script-itsel
+SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )"
+
 # Spin up a container with the Ubuntu 20.04 LTS image
-CONTAINER_ID=$(docker run --user docs --rm --detach readthedocs/build:$OS sleep $SLEEP)
+CONTAINER_ID=$(docker run --user docs --rm --detach --volume ${SCRIPT_DIR}/python-build.diff:/tmp/python-build.diff readthedocs/build:$OS sleep $SLEEP)
 echo "Running all the commands in Docker container: $CONTAINER_ID"
 
 # Install the tool version requested
 if [[ $TOOL == "python" ]]
 then
+    # Download list for all Python to force pyenv to be installed
+    docker exec $CONTAINER_ID asdf list all python &> /dev/null
+    # Patch pyenv to not update conda when installing pip
+    # https://github.com/pyenv/pyenv/issues/2070
+    docker exec $CONTAINER_ID patch -p0 /home/docs/.asdf/plugins/python/pyenv/plugins/python-build/bin/python-build /tmp/python-build.diff
+    # Remove .git because otherwise the patch is reset
+    docker exec $CONTAINER_ID rm -rf /home/docs/.asdf/plugins/python/pyenv/.git
+
     docker exec --env PYTHON_CONFIGURE_OPTS="--enable-shared" $CONTAINER_ID asdf install $TOOL $VERSION
 else
     docker exec $CONTAINER_ID asdf install $TOOL $VERSION

scripts/python-build.diff

@@ -0,0 +1,15 @@
+diff --git a/plugins/python-build/bin/python-build b/plugins/python-build/bin/python-build
+index a18680a4..ea976328 100755
+--- a/plugins/python-build/bin/python-build
++++ b/plugins/python-build/bin/python-build
+@@ -1042,7 +1042,9 @@ build_package_anaconda() {
+
+ build_package_miniconda() {
+   build_package_anaconda "$@"
+-  "${PREFIX_PATH}/bin/conda" install --yes "pip"
++  # Workaround to not upgrade conda when installing pip
++  # see https://github.com/pyenv/pyenv/issues/2070
++  "${PREFIX_PATH}/bin/conda" install --yes "pip" "conda=$(${PREFIX_PATH}/bin/conda --version | cut -d ' ' -f 2)"
+ }
+
+ build_package_copy() {