Fix: Properly close Docker client in DockerExecBox to prevent resource leakage (#2224)

opendevin/runtime/docker/exec_box.py

@@ -353,6 +353,7 @@ class DockerExecBox(Sandbox):
                     container.remove(force=True)
             except docker.errors.NotFound:
                 pass
+        self.docker_client.close()
 
     def get_working_directory(self):
         return self.sandbox_workspace_dir