Guess the Rec branch name on-the-fly as well for make_functor_Docs in CI

.gitlab-ci.yml

@@ -97,12 +97,13 @@ build-docs:
     # As the previous stage is allowed to fail, skip this stage if the previous
     # did not complete successfully (i.e. did not create the `run` symlink)
     - test -L run || { echo "WARNING build job failed, stopping"; exit 77; }
+    - TARGET_BRANCH=${CI_MERGE_REQUEST_TARGET_BRANCH_NAME:-${CI_COMMIT_BRANCH}}
   script:
     # First try producing just the graphs (gaudirun.py). If that fails, Moore
     # is likely incompatible with the last nightly, so fail with a warning.
     - ./run make -C doc graphs || { echo "WARNING build is incompatible with last nightly, stopping"; exit 77; }
     - reasons=
-    - ./run python doc/make_functor_docs.py "${CI_COMMIT_SHA:0:8}" "2024-patches" > doc/selection/thor_functors_reference.generated.rst || reasons+='ERROR failed functor docs build\n'
+    - ./run python doc/make_functor_docs.py "${CI_COMMIT_SHA:0:8}" "${TARGET_BRANCH}" > doc/selection/thor_functors_reference.generated.rst || reasons+='ERROR failed functor docs build\n'
     - ./run make -C doc linkcheck || reasons+='ERROR failed link check\n'
     - ./run make -C doc html || reasons+='ERROR failed html generation\n'
     - if [ -n "$reasons" ]; then echo -e $reasons; exit 1; fi