test(staged): remove redundant color cleanup

Author: chenjiahan

packages/rstack/tests/cli/staged/fmt.test.ts

@@ -45,7 +45,6 @@ beforeEach(() => {
     GIT_CONFIG_NOSYSTEM: '1',
     NO_COLOR: '1',
   };
-  delete env.FORCE_COLOR;
 
   git(['init', '--quiet']);
 });