Remove `🤖 automerge`

[arhadthedev]

According to python/core-workflow#498 (comment), the following steps must be done:

1. CI: Do not allow merge if labelled DO-NOT-MERGE #103337
2. Enable "Allow automerge" repo option on cpython, devguide, peps and core-workflow
3. Removed "automerge" label devguide#1082, Document the use of GitHub automerge devguide#1079
4. This PR is here
5. Remove automerge stuff miss-islington#610

Since step 5 was implemented before step 3 (and, probably, step 2), we cannot postpone removal of the https://github.com/python/cpython/labels/%3Arobot%3A%20automerge. Otherwise, core developers will continue to apply no longer working label.

[sobolevn]

сс @ezio-melotti

[hugovk]

Since step 5 was implemented before step 3 (and, probably, step 2),

Step 5 was merged on Thursday and step 2 was enabled on Wednesday. Sorry we didn't post about it in the issue.

Anyway, yes, let's remove the label now.

[hugovk]

And I have permissions to delete labels, so have deleted it. 🗑️

[arhadthedev]

For backup purposes: the label looked like this:

Because after I closed the tab, it's gone.