(GHA): Bump aquasecurity/trivy-action from 0.17.0 to 0.18.0 (#7)

Bumps [aquasecurity/trivy-action](https://github.com/aquasecurity/trivy-action) from 0.17.0 to 0.18.0.
- [Release notes](https://github.com/aquasecurity/trivy-action/releases)
- [Commits](aquasecurity/trivy-action@0.17.0...0.18.0)

---
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>

.github/workflows/pull-request-sast.yaml

@@ -20,7 +20,7 @@ jobs:
 
       # Results have to be a table as the organisation does not have Advanced Security license.
       - name: Run Trivy against Terraform
-        uses: aquasecurity/trivy-action@0.17.0
+        uses: aquasecurity/trivy-action@0.18.0
         with:
           scan-type: 'config'
           exit-code: '1'