src: only apply fix in main thread

PR-URL: nodejs#52702
Reviewed-By: Moshe Atlow <moshe@atlow.co.il>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Marco Ippolito <marcoippolito54@gmail.com>

test/parallel/test-process-load-env-file.js

@@ -58,13 +58,17 @@ describe('process.loadEnvFile()', () => {
     const originalCwd = process.cwd();
 
     try {
-      process.chdir(join(originalCwd, 'lib'));
+      if (common.isMainThread) {
+        process.chdir(join(originalCwd, 'lib'));
+      }
 
       assert.throws(() => {
         process.loadEnvFile();
       }, { code: 'ENOENT', syscall: 'open', path: '.env' });
     } finally {
-      process.chdir(originalCwd);
+      if (common.isMainThread) {
+        process.chdir(originalCwd);
+      }
     }
   });