build(deps): bump actions/setup-python from 5 to 6 (#11)

Bumps [actions/setup-python](https://github.com/actions/setup-python) from 5 to 6.
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](actions/setup-python@v5...v6)

---
updated-dependencies:
- dependency-name: actions/setup-python
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/ci.yaml

@@ -62,7 +62,7 @@ jobs:
           path: ${{ github.workspace }}/macvim-built-commit.txt
           key: macvim-built-commit-${{ steps.setup-env-vars.outputs.docs_commit}}-${{ steps.setup-env-vars.outputs.macvim_commit }}
 
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@v6
         with:
           python-version: '3.x'
           cache: 'pip'