mergify: add backport-v8.x always for main

[v1v]

Proposed commit message

Otherwise, backport-skip or any other backport- labels could have higher precedence and then backport-v8.x will not be attached.
If backport-8.x should always be there for any PRs targeting main, then this should help with.

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• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have made corresponding change to the default configuration files
• I have added tests that prove my fix is effective or that my feature works
• I have added an entry in CHANGELOG.next.asciidoc or CHANGELOG-developer.next.asciidoc.

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[botelastic]

This pull request doesn't have a Team:<team> label.

[ycombinator]

Hi @v1v, just wanted to check, how is this PR functionally different from #40718?

[v1v]

Hi @v1v, just wanted to check, how is this PR functionally different from #40718?

I think there is one edge case:

Someone can create a PR targeting main and add one backport-* label immediately after. In that case, the automation might not add the label backport-v8.x, see L134.

$ gh pr create --label backport-skip --fill --base main

I assume that an edge case could happen, so I decided to raise this PR to play it safe. Therefore, any new PR targeting main will be tagged with backport-v8.x regardless.

[ycombinator]

Gotcha. Makes sense. Thanks for thinking of the edge case and creating this PR (and similar ones in other repos too)!