build(deps): bump anchore/scan-action from 4 to 6

Bumps [anchore/scan-action](https://github.com/anchore/scan-action) from 4 to 6.
- [Release notes](https://github.com/anchore/scan-action/releases)
- [Changelog](https://github.com/anchore/scan-action/blob/main/CHANGELOG.md)
- [Commits](anchore/scan-action@v4...v6)

---
updated-dependencies:
- dependency-name: anchore/scan-action
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/scan-docker-images.yml

@@ -37,7 +37,7 @@ jobs:
       - name: Scan ${{ matrix.image }}
         id: scan
         continue-on-error: true
-        uses: anchore/scan-action@v4
+        uses: anchore/scan-action@v6
         with:
           image: ${{ matrix.image }}
           acs-report-enable: true