[REL-274] Prepare to release v0.13.5

The previous release did not successfully publish the python package to the CAR. The publish step failed with twine: command not found. @limonkufu has provided a fix for this issue, but in order to make use of it, we have to tweak our .gitlab-ci.yml. Also the OCI image was successfully published -- there is a 0.13.4 OCI image on the CAR. All things considered, it seems like another patch release is the way to go.

This MR tweaks the .gitlab-ci.yml, and bumps the version numbers in preparation to release.