Free more disk space on Linux CI.

.github/workflows/ci.yml

@@ -59,6 +59,8 @@ jobs:
             sudo rm -rf /usr/local/share/chromium
             sudo rm -rf /usr/local/lib/android
             sudo rm -rf /usr/local/lib/node_modules
+            sudo rm -rf "$AGENT_TOOLSDIRECTORY"
+            sudo docker image prune --all --force
             df -h
 
       - name: Install Native Dependencies (macOS)