Change the default value of keep_runtime_alive from True to False (#5288)

Author: tofarr

openhands/core/config/sandbox_config.py

@@ -36,7 +36,7 @@ class SandboxConfig:
 
     remote_runtime_api_url: str = 'http://localhost:8000'
     local_runtime_url: str = 'http://localhost'
-    keep_runtime_alive: bool = True
+    keep_runtime_alive: bool = False
     rm_all_containers: bool = False
     api_key: str | None = None
     base_container_image: str = 'nikolaik/python-nodejs:python3.12-nodejs22'  # default to nikolaik/python-nodejs:python3.12-nodejs22 for eventstream runtime