test: make sure test function resolves in test-worker-debug

Use the common `.then(common.mustCall())` check to verify that.
Also, we should not use `process.abort()` in `test/parallel`; if
the test fails, that leaves core dumps lying around on POSIX systems.

PR-URL: #28155
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

Author: addaleax

test/parallel/test-worker-debug.js

@@ -272,7 +272,7 @@ async function testWaitForDisconnectInWorker(session, post) {
 
   session.disconnect();
   console.log('Test done');
-})().catch((err) => {
+})().then(common.mustCall()).catch((err) => {
   console.error(err);
-  process.abort();
+  process.exitCode = 1;
 });