chore: add an initial .git-blame-ignore-revs

This adds the `.git-blame-ignore-revs` file which allows ignoring
certain commits when doing a `git blame --ignore-revs`

Ignore the commit that requires keyword arguments for
`register_custom_action()`

https://docs.github.com/en/repositories/working-with-files/using-files/viewing-a-file#ignore-commits-in-the-blame-view