⬆️ Bump step-security/harden-runner from 2.15.1 to 2.16.0 (#276)

Bumps [step-security/harden-runner](https://github.com/step-security/harden-runner) from 2.15.1 to 2.16.0.
- [Release notes](https://github.com/step-security/harden-runner/releases)
- [Commits](step-security/harden-runner@58077d3...fa2e9d6)

---
updated-dependencies:
- dependency-name: step-security/harden-runner
  dependency-version: 2.16.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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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@58077d3c7e43986b6b15fba718e8ea69e387dfcc # v2.15.1
+        uses: step-security/harden-runner@fa2e9d605c4eeb9fcad4c99c224cee0c6c7f3594 # v2.16.0
         with:
           egress-policy: audit