add: reusable workflow

Author: clmntsnr

.github/workflows/app-build-and-update-staging.yml

@@ -0,0 +1,40 @@
+# .github/workflows/app-build-reusable.yml (in AngleProtocol/github-workflows repository)
+
+name: Build and update staging (Reusable)
+
+on:
+  workflow_call:
+    inputs:
+      app:
+        required: true
+        type: string
+        description: 'The name of the app.'
+      image-url:
+        required: true
+        type: string
+        description: 'The URL of the Docker image.'
+      gcloud-credentials:
+        required: true
+        type: string
+        description: 'The Google Cloud credentials JSON.'
+
+    secrets:
+      GITHUB_TOKEN:
+        required: true
+      GCLOUD_CREDENTIALS:
+        required: true
+
+jobs:
+  build-image:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Build Image with Composite Action
+        uses: AngleProtocol/github-workflows/.github/actions/app-build.yml@main
+        with:
+          app: ${{ inputs.app }}
+          token: ${{ secrets.GITHUB_TOKEN }}
+          image-url: ${{ inputs.image-url }}
+          gcloud-credentials: ${{ inputs.gcloud-credentials }}
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GCLOUD_CREDENTIALS: ${{ secrets.GCLOUD_CREDENTIALS }}