chore(deps): bump actions/attest-build-provenance from 2 to 4

Bumps [actions/attest-build-provenance](https://github.com/actions/attest-build-provenance) from 2 to 4.
- [Release notes](https://github.com/actions/attest-build-provenance/releases)
- [Changelog](https://github.com/actions/attest-build-provenance/blob/main/RELEASE.md)
- [Commits](https://github.com/actions/attest-build-provenance/compare/v2...v4)

---
updated-dependencies:
- dependency-name: actions/attest-build-provenance
  dependency-version: '4'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/CI.yml

@@ -309,7 +309,7 @@ jobs:
           path: dist
 
       - name: Generate SLSA build provenance attestations
-        uses: actions/attest-build-provenance@v2
+        uses: actions/attest-build-provenance@v4
         with:
           subject-path: "dist/*"
 
@@ -436,7 +436,7 @@ jobs:
           cosign sign-blob --yes ferro-ta-rust-sbom.cdx.json     --output-signature ferro-ta-rust-sbom.cdx.json.sig     --output-certificate ferro-ta-rust-sbom.cdx.json.pem
 
       - name: Attest SBOM provenance
-        uses: actions/attest-build-provenance@v2
+        uses: actions/attest-build-provenance@v4
         with:
           subject-path: |
             ferro-ta-python-sbom.spdx.json