test: remove flakiness on macOS test

PR-URL: #56971
Refs: https://github.com/nodejs/node/actions/runs/13220154720/job/36904132463?pr=56970
Reviewed-By: Matteo Collina <[email protected]>
Reviewed-By: Marco Ippolito <[email protected]>

Author: anonrig

test/parallel/test-net-write-fully-async-hex-string.js

@@ -21,7 +21,7 @@ const server = net.createServer(common.mustCall(function(conn) {
       }
 
       while (conn.write(data, 'hex'));
-      globalThis.gc({ type: 'minor' });
+      globalThis.gc({ type: 'major' });
       // The buffer allocated inside the .write() call should still be alive.
     }