Add an empty line at the end.

Author: MGAMZ

mmengine/utils/package_utils.py

@@ -104,4 +104,4 @@ def call_command(cmd: list) -> None:
 
 def install_package(package: str):
     if not is_installed(package):
-        call_command(['python', '-m', 'pip', 'install', package])
+        call_command(['python', '-m', 'pip', 'install', package])