feat: add pgvector image build workflow and update cluster imageName

- Add build-pgvector-image.yml GH Actions workflow for GCR
- Set imageName to gcr.io/devops-lab-cluster/postgres-pgvector:15.2-0.8.0
- Image change only (CNPG rule: no config changes in same update)

.github/workflows/build-pgvector-image.yml

@@ -0,0 +1,46 @@
+name: Build pgvector image
+
+on:
+  workflow_dispatch:
+
+env:
+  REGISTRY: gcr.io/devops-lab-cluster
+  IMAGE_NAME: postgres-pgvector
+  IMAGE_TAG: "15.2-0.8.0"
+
+permissions:
+  contents: read
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Authenticate to GCR
+        uses: google-github-actions/auth@v2
+        with:
+          workload_identity_provider: "projects/*/locations/*/workloadIdentityPools/*/providers/*"
+          service_account: "github-deployer@devops-lab-cluster.iam.gserviceaccount.com"
+          token_format: access_token
+
+      - name: Docker Login to GCR
+        uses: docker/login-action@v3
+        with:
+          registry: gcr.io
+          username: _oauth2
+          password: ${{ steps.auth.outputs.access_token }}
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Build and push pgvector image
+        uses: docker/build-push-action@v5
+        with:
+          context: apps/base/customer1/hermes-db
+          file: apps/base/customer1/hermes-db/Dockerfile.postgres-pgvector
+          push: true
+          tags: "${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ env.IMAGE_TAG }}"
+          cache-from: type=gha
+          cache-to: type=gha,mode=max

apps/base/customer1/hermes-db/pg-cluster-hermes.yaml

@@ -9,6 +9,8 @@ spec:
   storage:
     size: 20Gi
 
+  imageName: gcr.io/devops-lab-cluster/postgres-pgvector:15.2-0.8.0
+
   postgresql: {}
 
   managed: