[MAINT] Change clang-format for pre-commit

[ndgrigorian]

This PR proposes

• moving to use mirrors-clang-format for clang-format
• adding .clang-format
• moving to clang-format-22 from clang-format-18

[Copilot]

Pull request overview

This PR updates the repository’s formatting/tooling setup to use mirrors-clang-format and a new .clang-format configuration, and removes the workflow’s manual installation of clang-format.

Changes:

• Switch pre-commit’s clang-format hook to pre-commit/mirrors-clang-format at v22.1.0.
• Add a repository .clang-format configuration file.
• Remove the GitHub Actions step that installs and symlinks clang-format-18.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
mkl/_mklinitmodule.c	Pure reformatting consistent with clang-format settings (no functional diff apparent in the provided hunk).
.pre-commit-config.yaml	Points clang-format hook to mirrors-clang-format v22.1.0.
.github/workflows/pre-commit.yml	Removes OS-level clang-format installation, relying on pre-commit hook instead.
.git-blame-ignore-revs	Adds revision entry for the formatting-only change.
.clang-format	Introduces clang-format configuration used by the hook.

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