Update dependency flake8 to v7

[renovate[bot]]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
flake8 (changelog)	^6.0.0 -> ^7.0.0

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Release Notes

pycqa/flake8 (flake8)

### [`v7.0.0`](https://togithub.com/pycqa/flake8/compare/6.1.0...7.0.0) [Compare Source](https://togithub.com/pycqa/flake8/compare/6.1.0...7.0.0)

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[softwarefactory-project-zuul[bot]]

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