CI: no need to trigger enable auto-merge when self-approve

[keradus]

as everyone needed have the powers to click enable auto-merge

@kubawerlos , please approve this PR if you can merge #7928 without anyone else touching that PR.

(everyone else, please skip those 2 PRs)

[coveralls]

coverage: 96.013%. remained the same
when pulling cb96b1c on keradus-patch-1
into 8b8fc66 on master.

[keradus]

looks like gh command to auto-merge is failing only when touching github workflows in PR (#7928 vs #7930). but it's also part that we want to self-approve. let's drop the auto-merge command as we can click it with UI.