test: normalize location test-worker-process-cwd.js runs tests

This change sets the process' directory to __dirname in order to
normalize where the test is ran.  This addresses the situation that
occurs when node is located in the root, and moving up a directory
results in the same directory.  In that case, an error was thrown
because the test interpreted this as a failed directory change.

Fixes: #28193
PR-URL: #28271
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Franziska Hinkelmann <franziska.hinkelmann@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Rich Trott <rtrott@gmail.com>

test/parallel/test-worker-process-cwd.js

@@ -10,6 +10,7 @@ if (!process.env.HAS_STARTED_WORKER) {
   if (!isMainThread) {
     common.skip('This test can only run as main thread');
   }
+  process.chdir(__dirname);
   const w = new Worker(__filename);
   process.chdir('..');
   w.on('message', common.mustCall((message) => {