Accept GitHub issues numbered only 32426 or above

[menkotoglou]

Fixes#504.

Iterates through the template file to find the gh-issue line and checks number if it's in the accepted issue number range.

This is how an unsuccessful attempt looks like:

❯ /bin/python3 /path/core-workflow/blurb/blurb.py
Error: The gh-issue number should be 32426 or above.
[Hit return to retry (or Ctrl-C to abort)>

[ghost]

All commit authors signed the Contributor License Agreement.

[hugovk]

Please could you add some tests?

Hopefully we can get #520 merged soon, then we can add unit tests.

In the meantime, tests are done by adding valid blurb files in the pass dir and invalid ones in the fail dir at https://github.com/python/core-workflow/tree/main/blurb/tests, and then running blurb test.

[menkotoglou]

Seems like the not_number case is already covered in the code. That's validated in the pre-existing invalid-gh-number.rst test case.

Also, the tests wouldn't pass if we didn't raise an exception at the class Blurbs level. Decided to move to the class definition level as I'm aligned with this approach.

Finally, retrospectively fixed some old tests that indeed were using smaller GH issue numbers.

[hugovk]

Thanks! It's nice when adding tests reveals a problem in the original implementation :)

Looks good, here's a wording suggestion.

[menkotoglou]

Thanks a lot for the review @hugovk. Suggestion commited!

[hugovk]

Thanks!

[pradyunsg]

A couple of non-blocking suggestions, with one of them being a nitpick that you're welcome to ignore if it's too much effort and a request to name a magic number.

[menkotoglou]

Thanks a lot for the review @pradyunsg. Feedback addressed already!

[menkotoglou]

Hey @pradyunsg, @hugovk, you think we're OK to merge this?

[hugovk]

Yes, let's merge. Thank you for your contribution!