chore: add chart-testing-config to workflow

Refs: CPLP-3362

.github/workflows/policy-hub-chart-test.yaml

@@ -103,7 +103,7 @@ jobs:
         run: ct lint --validate-maintainers=false --target-branch ${{ github.event.repository.default_branch }}
 
       - name: Run service chart-testing (install)
-        run: ct install --charts charts/policy-hub --helm-extra-set-args "--set=backend.policyhub.image=kind-registry:5000/policy-hub-service:testing --set=backend.policyhubmigrations.image=kind-registry:5000/policy-hub-migrations:testing"
+        run: ct install --charts charts/policy-hub --config charts/chart-testing-config.yaml --helm-extra-set-args "--set=backend.policyhub.image=kind-registry:5000/policy-hub-service:testing --set=backend.policyhubmigrations.image=kind-registry:5000/policy-hub-migrations:testing"
         if: github.event_name != 'pull_request' || steps.list-changed.outputs.changed == 'true'
 
         # currently the update is commented out, at the moment we're working for the initial version, after that the update will be enabled