Bump FairwindsOps/pluto from 5.18.2 to 5.18.6 (#38)

Bumps [FairwindsOps/pluto](https://github.com/fairwindsops/pluto) from 5.18.2 to 5.18.6.
- [Release notes](https://github.com/fairwindsops/pluto/releases)
- [Changelog](https://github.com/FairwindsOps/pluto/blob/master/.goreleaser.yml)
- [Commits](FairwindsOps/pluto@v5.18.2...v5.18.6)

---
updated-dependencies:
- dependency-name: FairwindsOps/pluto
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

.github/workflows/pull_request.yml

@@ -365,7 +365,7 @@ jobs:
       run: ct lint --target-branch=main --check-version-increment=false
 
     - name: Download Pluto
-      uses: FairwindsOps/pluto/[email protected].2
+      uses: FairwindsOps/pluto/[email protected].6
 
     - name: Scan for deprecated k8s APIs
       run: helm template cassandra-operator/ | pluto detect -