chore(deps): update step-security/harden-runner action to v2.18.0

Signed-off-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/publish-chart.yaml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Harden Runner
-        uses: step-security/harden-runner@f808768d1510423e83855289c910610ca9b43176 # v2.17.0
+        uses: step-security/harden-runner@6c3c2f2c1c457b00c10c4848d6f5491db3b629df # v2.18.0
         with:
           egress-policy: audit