CI: tools: directly copy prebuilt tools in container

Directly copy prebuilt tools in container instead of creating an
archieve and extracting it later in other workflows.

Update build workflow to support this new implementation.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>

.github/workflows/push-containers.yml

@@ -70,6 +70,10 @@ jobs:
           name: linux-buildbot-prebuilt-tools
           path: openwrt
 
+      - name: Extract prebuild tools
+        working-directory: openwrt
+        run: tar -xf tools.tar
+
       - name: Login to GitHub Container Registry
         uses: docker/login-action@v2
         with: