⬆️ Bump step-security/harden-runner from 2.21.0 to 2.21.1 (#761)

Bumps [step-security/harden-runner](https://github.com/step-security/harden-runner) from 2.21.0 to 2.21.1.
- [Release notes](https://github.com/step-security/harden-runner/releases)
- [Commits](step-security/harden-runner@05e3151...e14015d)

---
updated-dependencies:
- dependency-name: step-security/harden-runner
  dependency-version: 2.21.1
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

.github/workflows/push_gem.yml

@@ -24,7 +24,7 @@ jobs:
     steps:
       # Set up
       - name: Harden Runner
-        uses: step-security/harden-runner@05e31511f85b41b11d1cf0ef85d0992719546e2c # v2.21.0
+        uses: step-security/harden-runner@e14015d583714f6e62063499dc959a02595150a1 # v2.21.1
         with:
           egress-policy: audit