ci: configure docker driver and remove gha caching from build workflow

- Set explicit docker driver for setup-buildx-action
- Remove load option and gha cache configuration from base and final image builds
- Simplifies workflow to local docker builds only

Author: andrasbacsai

.github/workflows/build.yml

@@ -17,17 +17,16 @@ jobs:
 
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
+        with:
+          driver: docker
 
       - name: Build base image
         uses: docker/build-push-action@v6
         with:
           context: .
           file: ./Dockerfile.base
           push: false
-          load: true
           tags: openclaw-base:ci
-          cache-from: type=gha,scope=ci-base
-          cache-to: type=gha,mode=max,scope=ci-base
 
       - name: Build final image
         uses: docker/build-push-action@v6
@@ -38,5 +37,3 @@ jobs:
           build-args: |
             BASE_IMAGE=openclaw-base:ci
           tags: openclaw:ci
-          cache-from: type=gha,scope=ci-final
-          cache-to: type=gha,mode=max,scope=ci-final