Add .git-blame-ignore-revs file with black commit

[RobbeSneyders]

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

[coveralls]

Pull Request Test Coverage Report for Build 2572226601

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 94.707%

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Totals
Change from base Build 2570261384:	0.0%
Covered Lines:	2702
Relevant Lines:	2853

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💛 - Coveralls

[Ruwann]

Thanks!