Bump aquasecurity/trivy-action from 0.20.0 to 0.21.0 (#304)

Bumps [aquasecurity/trivy-action](https://github.com/aquasecurity/trivy-action) from 0.20.0 to 0.21.0.
- [Release notes](https://github.com/aquasecurity/trivy-action/releases)
- [Commits](aquasecurity/trivy-action@b2933f5...fd25fed)

---
updated-dependencies:
- dependency-name: aquasecurity/trivy-action
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -113,7 +113,7 @@ jobs:
           provenance: false
 
       - name: Run Trivy vulnerability scanner
-        uses: aquasecurity/trivy-action@b2933f565dbc598b29947660e66259e3c7bc8561 # 0.20.0
+        uses: aquasecurity/trivy-action@fd25fed6972e341ff0007ddb61f77e88103953c2 # 0.21.0
         continue-on-error: true
         with:
           image-ref: nginx/nginx-ingress-operator:${{ steps.meta.outputs.version }}