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

[DA-344]

Summary

This PR refactors the Client.run logic to fix problems involving asyncio due to how the library used the loop:

Needs testing

Exception

  File "/home/container/main.py", line 23, in <module>
    bot.run(BOT_TOKEN)

  File "/home/container/.local/lib/python3.11/site-packages/discord/client.py", line 772, in run
    loop.run_forever()

  File "/usr/local/lib/python3.11/asyncio/base_events.py", line 608, in run_forever
    self._run_once()

  File "/usr/local/lib/python3.11/asyncio/base_events.py", line 1936, in _run_once
    handle._run()

  File "/usr/local/lib/python3.11/asyncio/events.py", line 84, in _run
    self._context.run(self._callback, *self._args)

  File "/usr/local/lib/python3.11/asyncio/selector_events.py", line 956, in _read_ready
    self._read_ready_cb()

  File "/usr/local/lib/python3.11/asyncio/selector_events.py", line 988, in _read_ready__get_buffer
    self._protocol.buffer_updated(nbytes)

  File "/usr/local/lib/python3.11/asyncio/sslproto.py", line 439, in buffer_updated
    self._do_handshake()

  File "/usr/local/lib/python3.11/asyncio/sslproto.py", line 560, in _do_handshake
    self._sslobj.do_handshake()

  File "/usr/local/lib/python3.11/ssl.py", line 979, in do_handshake
    self._sslobj.do_handshake()

Information

• This PR fixes an issue.
• This PR adds something new (e.g. new method or parameters).
• This PR is a breaking change (e.g. methods or parameters removed/renamed).
• This PR is not a code change (e.g. documentation, README, typehinting,
  examples, ...).

Checklist

• I have searched the open pull requests for duplicates.
• If code changes were made then they have been tested.
  • I have updated the documentation to reflect the changes.
• If type: ignore comments were used, a comment is also left explaining why.
• I have updated the changelog to include these changes.

[DA-344]

Applied all the changes Dorukyum requested.

Before merging, I would like some feedback on this discussion message

[DA-344]

Pls fix Luma's issue

This has been fixed on the latest commit.

[Lumabots]

I'll review and test that around 1pm

[Paillat-dev]

Still having issues. Seems like changing to _loop in DiscordWebSocket fixes it but I'll let you confirm.

INFO:discord.client:logging in using static token
Traceback (most recent call last):
  File "C:\Users\jerem\Documents\pycord\pycord\test_client_async.py", line 39, in <module>
    asyncio.run(main())
  File "C:\Users\jerem\AppData\Roaming\uv\python\cpython-3.12.11-windows-x86_64-none\Lib\asyncio\runners.py", line 195, in run
    return runner.run(main)
           ^^^^^^^^^^^^^^^^
  File "C:\Users\jerem\AppData\Roaming\uv\python\cpython-3.12.11-windows-x86_64-none\Lib\asyncio\runners.py", line 118, in run
    return self._loop.run_until_complete(task)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\jerem\AppData\Roaming\uv\python\cpython-3.12.11-windows-x86_64-none\Lib\asyncio\base_events.py", line 691, in run_until_complete
    return future.result()
           ^^^^^^^^^^^^^^^
  File "C:\Users\jerem\Documents\pycord\pycord\test_client_async.py", line 33, in main
    await bot.start(os.getenv("TOKEN_2", ""))
  File "C:\Users\jerem\Documents\pycord\pycord\discord\client.py", line 872, in start
    await self.connect(reconnect=reconnect)
  File "C:\Users\jerem\Documents\pycord\pycord\discord\client.py", line 759, in connect
    self.ws = await asyncio.wait_for(coro, timeout=60.0)
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\jerem\AppData\Roaming\uv\python\cpython-3.12.11-windows-x86_64-none\Lib\asyncio\tasks.py", line 520, in wait_for
    return await fut
           ^^^^^^^^^
  File "C:\Users\jerem\Documents\pycord\pycord\discord\gateway.py", line 348, in from_client
    ws = cls(socket, loop=client.loop)
                          ^^^^^^^^^^^
  File "C:\Users\jerem\Documents\pycord\pycord\discord\client.py", line 367, in loop
    raise RuntimeError("loop is not set")
RuntimeError: loop is not set
ERROR:asyncio:Unclosed client session
client_session: <aiohttp.client.ClientSession object at 0x0000019183896540>
ERROR:asyncio:Unclosed connector
connections: ['deque([(<aiohttp.client_proto.ResponseHandler object at 0x00000191843B9A30>, 47503.546)])']
connector: <aiohttp.connector.TCPConnector object at 0x0000019183A48F80>

Test Code

import os
from discord import *
import asyncio
import logging

from dotenv import load_dotenv

logging.basicConfig(level=logging.INFO)

load_dotenv()

bot = Bot(intents=Intents.all())


class MyCog(Cog):
    """Example cog for the bot"""

    def __init__(self, bot: Bot):
        self.bot: Bot = bot

    @Cog.listener()
    async def on_ready(self):
        print(f"Logged in as {self.bot.user} (ID: {self.bot.user.id})")


async def load_cogs():
    bot.add_cog(MyCog(bot))

async def main():
    await load_cogs()

    try:
        await bot.start(os.getenv("TOKEN_2", ""))
    except KeyboardInterrupt:
        await bot.close()


if __name__ == "__main__":
    asyncio.run(main())

Edit, no, that's not all, if you leave it running for some time after, leads to

Exception in thread Thread-1:
Traceback (most recent call last):
  File "C:\Users\jerem\AppData\Roaming\uv\python\cpython-3.12.11-windows-x86_64-none\Lib\threading.py", line 1075, in _bootstrap_inner
    self.run()
  File "C:\Users\jerem\Documents\pycord\pycord\discord\gateway.py", line 167, in run
    f = asyncio.run_coroutine_threadsafe(coro, loop=self.ws.loop)
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\jerem\AppData\Roaming\uv\python\cpython-3.12.11-windows-x86_64-none\Lib\asyncio\tasks.py", line 950, in run_coroutine_threadsafe
    loop.call_soon_threadsafe(callback)
    ^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'call_soon_threadsafe'
C:\Users\jerem\AppData\Roaming\uv\python\cpython-3.12.11-windows-x86_64-none\Lib\threading.py:1077: RuntimeWarning: coroutine 'DiscordWebSocket.send_heartbeat' was never awaited
  self._invoke_excepthook(self)
RuntimeWarning: Enable tracemalloc to get the object allocation traceback
WARNING:discord.gateway:Can't keep up, shard ID None websocket is 49.8s behind.
WARNING:discord.gateway:Can't keep up, shard ID None websocket is 99.4s behind.
WARNING:discord.gateway:Can't keep up, shard ID None websocket is 149.0s behind.

[Lumabots]

test and works great with and without my overlap pr, no idea about paillat issue tho

[Paillat-dev]

Alright looks good, can't find any problem. Merge coflicts, and @Lumabots please test your loop stuff one last time with the latest changes.

[Lumabots]

tested and no issue with #2771

[Lumabots]

LGTM

[Paillat-dev]

@Lulalaby when your merge this (once review is good) pls make sure to squash so that we can put it in rc2 and then revert it easily if problems

[Paillat-dev]

Luma comment