ci: fix caching

.github/workflows/build.yml

@@ -52,7 +52,9 @@ jobs:
     - uses: actions/cache/save@v5
       if: steps.restore-cache.outputs.cache-hit != 'true'
       with:
-        path: ~/.gradle/caches/
+        path: |
+          ~/.gradle/caches/
+          api/
         key: ${{ steps.restore-cache.outputs.cache-primary-key }}
 
     - name: build