test: remove unused "e" from catch in http2 test

PR-URL: #23476
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Shelley Vohr <codebytere@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>

Author: Stephen Heitman

test/parallel/test-http2-respond-file-fd-invalid.js

@@ -25,7 +25,7 @@ server.on('stream', (stream) => {
   // Get first known bad file descriptor.
   try {
     while (fs.fstatSync(++fd));
-  } catch (e) {
+  } catch {
     // do nothing; we now have an invalid fd
   }