👷 Add GH workflow to bump pre-commit hook versions

[YuriiMotov]

This PR adds a GH workflow to bump pre-commit hooks using prek auto-update --freeze --cooldown-days 7 command.

Note: this workflow re-uses existing LATEST_CHANGES token as it's done in prepare-release.yml for other repos.

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Same as fastapi/fastapi#15873 (except token name FASTAPI_PR_TOKEN -> LATEST_CHANGES)

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Note: to make it work, the following 3 labels must exist in the repo:

• internal
• dependencies
• pre-commit