test: fix module loading error for AIX 7.1

AIX 7.1 appears to return a different error message compared to AIX 6.1.

PR-URL: https://github.com/nodejs/node/pull/25418
Reviewed-By: Beth Griggs <Bethany.Griggs@uk.ibm.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: George Adams <george.adams@uk.ibm.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>

test/parallel/test-module-loading-error.js

@@ -30,7 +30,8 @@ const errorMessagesByPlatform = {
   sunos: ['unknown file type', 'not an ELF file'],
   darwin: ['file too short'],
   aix: ['Cannot load module',
-        'Cannot run a file that does not have a valid format.']
+        'Cannot run a file that does not have a valid format.',
+        'Exec format error']
 };
 // If we don't know a priori what the error would be, we accept anything.
 const errorMessages = errorMessagesByPlatform[process.platform] || [''];