lib: remove unnecessary assignment of exports

This commit removes the assignment of exports since it is not used
in these files and there is no harm re-assigning module.exports.

PR-URL: #20143
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Jackson Tian <shyvo1987@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>

Author: danbev

lib/internal/errors.js

@@ -687,7 +687,7 @@ function isStackOverflowError(err) {
          err.message === maxStack_ErrorMessage;
 }
 
-module.exports = exports = {
+module.exports = {
   dnsException,
   errnoException,
   exceptionWithHostPort,

lib/os.js

@@ -159,7 +159,7 @@ function networkInterfaces() {
   }, {});
 }
 
-module.exports = exports = {
+module.exports = {
   arch,
   cpus,
   endianness,

lib/v8.js

@@ -213,7 +213,7 @@ function deserialize(buffer) {
   return der.readValue();
 }
 
-module.exports = exports = {
+module.exports = {
   cachedDataVersionTag,
   getHeapStatistics,
   getHeapSpaceStatistics,