Remove variables export from test-only job

LGTM

Committed/pushed to 11.x and cherry-picked to 10.1.x, thanks!

For info, in the contrib gitlab template we changed this so that the variables can be exported, but are not done by default. Also even when exported, the personal gitlab variables are removed. See #3388207: Allow showing debug information → and the associated MR gitlab_templates/-/merge_requests/45

Thanks. If this will be beneficial for core, let's create a child issue here 🌱 [meta] GitLab CI feature parity with DrupalCI Active , so that something similar can be added to core as well (this fix was only about the test-only job, but I think that we would then want to allow exports for all jobs, not only this one).

Automatically closed - issue fixed for 2 weeks with no activity.