fix(ext.bridge): fix groups missing parent attr

[Middledot]

Summary

self-explanatory
Fix #1816

Test code used

class Bot(bridge.Bot):
    def __init__(self):
        intents = discord.Intents.all()
        intents.presences = False
        super().__init__(
            intents=intents,
            command_prefix="::",
            case_insensitive=True,
            enable_debug_events=True,
            strip_after_prefix=True,
            description="something...",
            help_command=commands.DefaultHelpCommand()
        )

bot = Bot()
bot.load_extension("jishaku")

class Test(commands.Cog):
    @bridge.bridge_group(invoke_without_command=False)
    async def layer(self, ctx):
        await ctx.respond("hello!!!")

    @layer.command(invoke_without_command=False)
    async def one(self, ctx):
        await ctx.respond("All systems green")

bot.add_cog(Test())

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.

[BobDotCom]

Please add a changelog entry

[Nzii3]

Please add a changelog entry

Where?

[Lulalaby]

Please add a changelog entry

Where?

In deez nuts :3

[Lulalaby]

just kidding https://github.com/Middledot/pycord/blob/bridge-fix/CHANGELOG.md

[Nzii3]

just kidding https://github.com/Middledot/pycord/blob/bridge-fix/CHANGELOG.md

Crap I thought this was my pr :/

[Lulalaby]

just kidding https://github.com/Middledot/pycord/blob/bridge-fix/CHANGELOG.md

Crap I thought this was my pr :/

LMFAO

[Middledot]

Apologies for the delay, the entry is added