Bump actions/attest-build-provenance from 1.4.2 to 1.4.3 (pyca#11554)

Bumps [actions/attest-build-provenance](https://github.com/actions/attest-build-provenance) from 1.4.2 to 1.4.3.
- [Release notes](https://github.com/actions/attest-build-provenance/releases)
- [Changelog](https://github.com/actions/attest-build-provenance/blob/main/RELEASE.md)
- [Commits](actions/attest-build-provenance@6149ea5...1c608d1)

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

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

Author: dependabot[bot]

.github/workflows/pypi-publish.yml

@@ -93,7 +93,7 @@ jobs:
       # Do not perform attestation for things for TestPyPI. This is because
       # there's nothing that would prevent a malicious PyPI from serving a
       # signed TestPyPI asset in place of a release intended for PyPI.
-      - uses: actions/attest-build-provenance@6149ea5740be74af77f260b9db67e633f6b0a9a1  # v1.4.2
+      - uses: actions/attest-build-provenance@1c608d11d69870c2092266b3f9a6f3abbf17002c  # v1.4.3
         with:
           subject-path: 'dist/**/cryptography*'
         if: env.TWINE_REPOSITORY == 'pypi'