try a simpler workflow to get things working

.github/workflows/develocity.yml

@@ -0,0 +1,25 @@
+name: Develocity testbed
+
+on:
+  push:
+  workflow_dispatch:
+
+env:
+  DEVELOCITY_ACCESS_KEY: ${{ secrets.DEVELOCITY_ACCESS_KEY }}
+
+jobs:
+  develocity:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Java
+        uses: actions/setup-java@v4
+        with:
+          java-version: 17
+          distribution: 'zulu'
+          server-id: central
+
+      - name: Build without Tests
+        run: ./mvnw -U install -DskipTests