ccache should not be included in build artifacts

In my build two weeks ago build artifacts worked as expected:

Uploading artifacts...
/builds/mariadb-team/mariadb-10.3/debian/output/: found 32 matching files
Uploading artifacts to coordinator... ok 

However when I made a new build after a two week pause, it failed with:

Uploading artifacts...
/builds/mariadb-team/mariadb-10.3/debian/output/: found 6684 matching files
ERROR: Uploading artifacts to coordinator... too large archive
=413 Request Entity Too Large 

The ccache cache is stored in debian/output/.ccache. For some reason Gitlab-CI ignored it previously from build artifacts but now started to include it.

I am unable to track down what change caused this. Did a new Gitlab-CI version change the behavior? There are a lot of changes in salsa-ci.yml, was is something there? I've read the git commits but can't figure this one out. Please advise.