refactor: Update Client.run to have a better async I/O usage

CHANGELOG.md

@@ -21,6 +21,8 @@ These changes are available on the `master` branch, but have not yet been releas
 
 - Manage silence for new SSRC with existing user_id.
   ([#2808](https://github.com/Pycord-Development/pycord/pull/2808))
+- Fixed Async I/O errors that could be raised when using `Client.run`.
+  ([#2645](https://github.com/Pycord-Development/pycord/pull/2645))
 
 ### Removed
 

discord/bot.py

@@ -1386,7 +1386,7 @@ def before_invoke(self, coro):
         TypeError
             The coroutine passed is not actually a coroutine.
         """
-        if not asyncio.iscoroutinefunction(coro):
+        if not inspect.iscoroutinefunction(coro):
             raise TypeError("The pre-invoke hook must be a coroutine.")
 
         self._before_invoke = coro
@@ -1418,7 +1418,7 @@ def after_invoke(self, coro):
             The coroutine passed is not actually a coroutine.
 
         """
-        if not asyncio.iscoroutinefunction(coro):
+        if not inspect.iscoroutinefunction(coro):
             raise TypeError("The post-invoke hook must be a coroutine.")
 
         self._after_invoke = coro