bug: fix incorrect prefix for image (#929)

/kind bug
/area ci

* fixes bug where $IMG had incorrect registry prefix
* adds docker pull command to ensure that image is in local docker context before importing

.github/workflows/ui-tests-periodic.yaml

@@ -20,7 +20,8 @@ jobs:
           sudo echo "127.0.0.1 local.kyma.dev" | sudo tee -a /etc/hosts
           wget -q -O - https://raw.githubusercontent.com/k3d-io/k3d/main/install.sh | sudo bash
           sha=$(./scripts/get_latest_build_sha.sh)
-          IMG=europe-docker.pkg.dev/kyma-project/dev/istio-manager:"$sha" ./tests/ui/scripts/k3d-ci-kyma-dashboard-integration.sh stage
+          docker pull europe-docker.pkg.dev/kyma-project/prod/istio-manager:"$sha"
+          IMG=europe-docker.pkg.dev/kyma-project/prod/istio-manager:"$sha" ./tests/ui/scripts/k3d-ci-kyma-dashboard-integration.sh stage
       - uses: actions/upload-artifact@v4
         if: always()
         name: Export Cypress output