[StepSecurity] ci: Harden GitHub Actions (#3379)

Signed-off-by: StepSecurity Bot <[email protected]>
Co-authored-by: Lalit Kumar Bhasin <[email protected]>

Author: step-security-bot

.github/workflows/benchmark.yml

@@ -13,6 +13,11 @@ jobs:
     name: Run OpenTelemetry-cpp benchmarks
     runs-on: ubuntu-latest
     steps:
+      - name: Harden the runner (Audit all outbound calls)
+        uses: step-security/harden-runner@0634a2670c59f64b4a01f0f96f84700a4088b9f0 # v2.12.0
+        with:
+          egress-policy: audit
+
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           submodules: 'recursive'
@@ -47,6 +52,11 @@ jobs:
     name: Store benchmark result
     runs-on: ubuntu-latest
     steps:
+      - name: Harden the runner (Audit all outbound calls)
+        uses: step-security/harden-runner@0634a2670c59f64b4a01f0f96f84700a4088b9f0 # v2.12.0
+        with:
+          egress-policy: audit
+
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # main March 2025
         with: