chore: refactor re-usable workflows to enable re-use in derived repositories

.github/workflows/wc-build-push.yml

@@ -7,13 +7,25 @@ on:
       flavor:
         required: true
         type: string
+      registry:
+        description: "Docker registry to push built containers to"
+        required: false
+        type: string
+        default: "ghcr.io"
+    secrets:
+      DOCKER_USERNAME:
+        description: "User name for Docker login, if not provided the GitHub actor will be used"
+        required: false
+      DOCKER_PASSWORD:
+        description: "Password or token for Docker login, if not provided the GITHUB_TOKEN will be used"
+        required: false
 
 permissions:
   contents: read
 
 env:
   CONTAINER_FLAVOR: ${{ inputs.flavor }}
-  REGISTRY: ghcr.io
+  REGISTRY: ${{ inputs.registry }}
 
 jobs:
   build-push:
@@ -33,10 +45,13 @@ jobs:
           persist-credentials: false
       - uses: docker/setup-buildx-action@e468171a9de216ec08956ac3ada2f0791b6bd435 # v3.11.1
       - uses: docker/login-action@5e57cd118135c172c3672efd75eb46360885c0ef # v3.6.0
+        env:
+          USERNAME: ${{ secrets.DOCKER_USERNAME || github.actor }}
+          PASSWORD: ${{ secrets.DOCKER_PASSWORD || secrets.GITHUB_TOKEN }}
         with:
           registry: ${{ env.REGISTRY }}
-          username: ${{ github.actor }}
-          password: ${{ secrets.GITHUB_TOKEN }}
+          username: ${{ env.USERNAME }}
+          password: ${{ env.PASSWORD }}
       - uses: docker/metadata-action@c1e51972afc2121e065aed6d45c65596fe445f3f # v5.8.0
         env:
           DOCKER_METADATA_SET_OUTPUT_ENV: false