fix: remove command always showing help instead of executing (#823)

The help flag check used `helpArg != null` but addFlag always returns
a bool (false when not specified), never null. This caused the remove
command to always print help and exit without executing.

Changed to `helpArg == true` to match the same pattern used in
create.dart.

Fixes #822, Fixes #804, Fixes #786

Author: ersanKolay

bin/remove.dart

@@ -25,9 +25,9 @@ void main(List<String> args) {
 
   final parsedArgs = parser.parse(args);
 
-  final helpArg = parsedArgs[ArgEnums.help.name];
+  final helpArg = parsedArgs[ArgEnums.help.name] as bool?;
 
-  if (helpArg != null) {
+  if (helpArg == true) {
     // ignore_for_file: avoid_print
     print(parser.usage);
     return;