test: use global.gc() instead of gc()

This change is made for consistency, and to remove an
eslint-disable comment.

PR-URL: #25012
Reviewed-By: Сковорода Никита Андреевич <[email protected]>
Reviewed-By: Ruben Bridgewater <[email protected]>
Reviewed-By: Richard Lau <[email protected]>
Reviewed-By: Luigi Pinca <[email protected]>
Reviewed-By: Jeremiah Senkpiel <[email protected]>
Reviewed-By: Rich Trott <[email protected]>

Author: cjihrig

test/parallel/test-fs-filehandle.js

@@ -31,6 +31,6 @@ common.expectWarning({
   ]
 });
 
-gc();  // eslint-disable-line no-undef
+global.gc();
 
 setTimeout(() => {}, 10);