Experiment with caching the Develocity local cache

This can be useful when pushing small iterations to a pull request.

It is limited to pull requests only and only for the Initial JDK build.
We will check if it improves things and the size of the cache.

Related to quarkusio#43559

.github/workflows/ci-actions-incremental.yml

@@ -165,6 +165,14 @@ jobs:
           restore-keys: |
             ${{ steps.cache-key.outputs.m2-monthly-branch-cache-key }}-
             ${{ steps.cache-key.outputs.m2-monthly-cache-key }}-
+      - name: Cache Develocity local cache
+        uses: actions/cache@v4
+        if: github.event_name == 'pull_request'
+        with:
+          path: ~/.m2/.develocity/build-cache
+          key: develocity-cache-Initial JDK 17 Build-${{ github.event.pull_request.number }}-${{ github.event.pull_request.head.sha }}
+          restore-keys: |
+            develocity-cache-Initial JDK 17 Build-${{ github.event.pull_request.number }}-
       - name: Populate the cache
         run: |
           ./mvnw -T2C $COMMON_MAVEN_ARGS dependency:go-offline