Fix self.channel can be None if is DM

[AlbertUnruh]

About

This PR fixes a bug where self.channel can be None.

(The actual bug isn't fixed since the channel-property would have to be asynchronous, but one case where channel.id is used is fixed...)

Checklist

• The pre-commit code linter has been run over all edited files to ensure the code is linted.
• I've ensured the change(s) work on 3.8.6 and higher.
• I have added the versionadded, versionchanged and deprecated to any new or changed user-facing function I committed.

Pull-Request specification

I've made this pull request: (check all that apply)

• For the documentation
• To add a new feature
• As a general enhancement
• As a refactor of the library/the library's code
• To fix an existing bug
• To resolve #ISSUENUMBER

This is:

• A breaking change

*Inside Prefixed Commands

Traceback before applying the fix:

  File "/home/albert/PycharmProjects/Alberto-X3-V4/extensions/administration/sudo/ext.py", line 80, in sudo
    await ctx.reply("test...")
  File "/home/albert/.local/share/virtualenvs/Alberto-X3-V4-WQLHrZIA/lib/python3.11/site-packages/interactions/ext/prefixed_commands/context.py", line 98, in reply
    return await self.send(content=content, reply_to=self.message, embeds=embeds or embed, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/albert/.local/share/virtualenvs/Alberto-X3-V4-WQLHrZIA/lib/python3.11/site-packages/interactions/client/mixins/send.py", line 97, in send
    message_data = await self._send_http_request(message_payload, files=files or file)
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/albert/.local/share/virtualenvs/Alberto-X3-V4-WQLHrZIA/lib/python3.11/site-packages/interactions/ext/prefixed_commands/context.py", line 76, in _send_http_request
    return await self.client.http.create_message(message_payload, self.channel.id, files=files)
                                                                  ^^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'id'