ci(docker-nightly): add check for new commits

- check for commits in the last 24 hours and only run if there
were some.
- add option to ignore check and definitely build image

.github/workflows/docker-nightly-image.yml

@@ -18,15 +18,33 @@ on:
         description: 'Name of the docker tag to create.'
         required: true
         default: 'nightly'
+      ignore-24h-commit-check:
+        description: 'Build image regardless of last commit date.'
+        required: true
+        type: boolean
+        default: false
       user:
         description: ''
         required: false
         default: 'schedule'
 
 jobs:
-  build:
+  check-commits:
     runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/[email protected]
+        with:
+          repository: ${{ github.event.inputs.repository || 'GIScience/openrouteservice' }}
+          ref: ${{ github.event.inputs.branch || 'main' }}
+
+      - name: Check for new commits since 24 h ago
+        run: echo "NEW_COMMIT_COUNT=$(git log --oneline --since '24 hours ago' | wc -l)" >> $GITHUB_ENV
 
+  build:
+    needs: check-commits
+    runs-on: ubuntu-latest
+    if: ${{ github.event.inputs.ignore-24h-commit-check || env.NEW_COMMIT_COUNT > 0 }}
     steps:
       - name: Checkout
         uses: actions/[email protected]