ci: fix sphinx-multiversion tag detection in CI

- add GIT_DEPTH: 0 to build-docs job for full clone
- add explicit git fetch --tags to ensure all tags are available
- add debug commands to troubleshoot tag/branch availability
- add sphinx-multiversion --dump-metadata for version detection

This should fix the issue where v3.0.0 tag was not being picked up
by sphinx-multiversion in GitLab CI, even though it works locally.

.gitlab-ci.yml

@@ -47,14 +47,24 @@ secret_detection:
 build-docs:
   stage: build-docs
   image: python:3
+  variables:
+    GIT_DEPTH: 0 # Ensure full clone for sphinx-multiversion
   before_script:
     - python -m pip install --upgrade pip
     - pip install -r requirements.txt
     - pip install -r requirements-doc.txt
     - git fetch --unshallow || true # Ensure we have full git history for multiversion
+    - git fetch origin --tags || true # Ensure all tags are fetched from origin
     - git config --global --add safe.directory $CI_PROJECT_DIR
   script:
+    - echo "Current commit:" $CI_COMMIT_SHA
+    - echo "Current tag:" $CI_COMMIT_TAG
+    - echo "Current branch:" $CI_COMMIT_BRANCH
+    - git tag -l
+    - git branch -a
     - cd docs
+    - echo "Sphinx-multiversion detected versions:"
+    - sphinx-multiversion --dump-metadata source build/multiversion/html
     - make multiversion
   artifacts:
     paths: