lib: remove debugger dead code

PR-URL: #18426
Refs: 719247f
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Franziska Hinkelmann <franziska.hinkelmann@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Eugene Ostroukhov <eostroukhov@google.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Jon Moss <me@jonathanmoss.me>
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

lib/internal/bootstrap_node.js

@@ -60,11 +60,7 @@
     NativeModule.require('internal/trace_events_async_hooks').setup();
     NativeModule.require('internal/inspector_async_hook').setup();
 
-    // Do not initialize channel in debugger agent, it deletes env variable
-    // and the main thread won't see it.
-    if (process.argv[1] !== '--debug-agent')
-      _process.setupChannel();
-
+    _process.setupChannel();
     _process.setupRawDebug();
 
     const browserGlobals = !process._noBrowserGlobals;