chore(deps): bump actions/attest-build-provenance in the actions group (#5468)

Bumps the actions group with 1 update: [actions/attest-build-provenance](https://github.com/actions/attest-build-provenance).


Updates `actions/attest-build-provenance` from 2.0.1 to 2.1.0
- [Release notes](https://github.com/actions/attest-build-provenance/releases)
- [Changelog](https://github.com/actions/attest-build-provenance/blob/main/RELEASE.md)
- [Commits](c4fbc64884...7668571508)

---
updated-dependencies:
- dependency-name: actions/attest-build-provenance
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: actions
...

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

.github/workflows/pip.yml

@@ -103,7 +103,7 @@ jobs:
     - uses: actions/download-artifact@v4
 
     - name: Generate artifact attestation for sdist and wheel
-      uses: actions/attest-build-provenance@c4fbc648846ca6f503a13a2281a5e7b98aa57202 # v2.0.1
+      uses: actions/attest-build-provenance@7668571508540a607bdfd90a87a560489fe372eb # v2.1.0
       with:
         subject-path: "*/pybind11*"