fix: Python dependency sync check is never executed in CI/CD workflow

The step *Check that compiled Python dependency manifests are up-to-date with their sources*
is supposed to run only for the lowest supported Python version (currently 3.8).
However, commit 751adb0 inadvertently disabled
this step for all Python versions because of an incorrect string comparison
(`3.8.` is not a substring of `3.8`).

Author: jtrobles-cdd

.github/workflows/ci.yaml

@@ -138,7 +138,7 @@ jobs:
 
       - name: Check that compiled Python dependency manifests are up-to-date with their sources
         # FIXME: There are issues related to testing with multiple Python versions.
-        if: ${{ startsWith(matrix.python_version, '3.8.') }}
+        if: ${{ startsWith(steps.set_up_python.outputs.python-version, '3.8.') }}
         run: |
           source "$PYTHON_VIRTUALENV_ACTIVATE"
           make python-deps-sync-check