build(deps): bump sigstore/sigstore-conformance in the actions group (#1760)

Bumps the actions group with 1 update: [sigstore/sigstore-conformance](https://github.com/sigstore/sigstore-conformance).


Updates `sigstore/sigstore-conformance` from 0.0.26 to 0.0.27
- [Release notes](https://github.com/sigstore/sigstore-conformance/releases)
- [Commits](sigstore/sigstore-conformance@9611941...4d66ba3)

---
updated-dependencies:
- dependency-name: sigstore/sigstore-conformance
  dependency-version: 0.0.27
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: actions
...

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

Author: dependabot[bot]

.github/workflows/conformance.yml

@@ -28,7 +28,7 @@ jobs:
       - name: install sigstore-python
         run: python -m pip install .
 
-      - uses: sigstore/sigstore-conformance@9611941d54398f2e3f6383b6f744442a56d2fb2a # v0.0.26
+      - uses: sigstore/sigstore-conformance@4d66ba3cb0c9c95f705c757c0f5e226d3f4d5151 # v0.0.27
         with:
           entrypoint: ${{ github.workspace }}/test/integration/sigstore-python-conformance
           xfail: "test_verify*intoto-with-custom-trust-root] test_verify*managed-key-happy-path] test_verify*managed-key-and-trusted-root]" # see issues 1442, 1244