[bugfix] Rename gitlab variable
According to https://gitlab.com/gitlab-org/gitlab/-/issues/352957
the variable name CI_BUILD_REF_NAME
is deprecated since gitlab 9.0
and was finally removed in gitlab 16.0. The new name of this variable
since gitlab 9.0 is CI_COMMIT_REF_NAME
.
Hence, to keep our branch name matching feature working, we have to adjust to the renaming.
Warning: This patch simply replaces the variable name. I did not do any further checks of the script.