automatically build newer nextcloud versions when they have ripened half a year

.forgejo/workflows/build_nextcloud.yml

@@ -10,16 +10,40 @@ on:
     - cron: "@daily"
 
 jobs:
-  build-container:
-    name: Build Nextcloud ${{ matrix.nextcloud-version }} Image
+  get-versions:
+    name: Determine viable Nextcloud versions
     runs-on: docker
+    container:
+      image: docker.io/library/python:3.14-slim
+
+    outputs:
+      versions: ${{ steps.matrix.outputs.versions }}
+
+    steps:
+      - name: Install required system package
+        run: apt-get update; apt-get install -y --no-install-recommends --no-install-suggests nodejs
+
+      - name: Install required pip package
+        run: pip install requests
+
+      - name: Checkout source code
+        uses: actions/checkout@v7
+
+      - name: Generate Nextcloud version matrix
+        id: matrix
+        shell: sh
+        run: python3 ${{ forgejo.workspace }}/nextcloud/get_versions_to_be_built.py
+
+  build-container:
+    name: Build Nextcloud Image
+    runs-on: docker
+    needs: get-versions
     container:
       image: ghcr.io/osscontainertools/kaniko:alpine
     strategy:
       matrix:
-        nextcloud-version:
-          # renovate: datasource=docker depName=docker.io/library/nextcloud
-          - 34
+        nextcloud-version: ${{ fromJSON(needs.get-versions.outputs.versions) }}
+
     steps:
       - name: Install required system packages
         run: apk add --no-cache nodejs git