feat: add REQUIRE_TAG and make channel flags editable

[AstreaTSS]

Pull Request Type

• Feature addition
• Bugfix
• Documentation update
• Code refactor
• Tests improvement
• CI/CD pipeline enhancement
• Other: [Replace with a description]

Description

This PR adds the REQUIRE_TAG flag to ChannelFlags, and makes channel flags editable.

(Technically this is two features in one, but they fit together.)

Changes

See description.

Related Issues

Fixes #1673

Test Scenarios

import interactions as ipy

@ipy.slash_command("test", description="test!")
async def test(ctx: ipy.SlashContext):
    chan: ipy.GuildForum = await bot.fetch_channel(FORUM_CHANNEL)
    await chan.edit(flags=ipy.ChannelFlags.REQUIRE_TAG)
    await ctx.send("Done!")

Python Compatibility

• I've ensured my code works on Python 3.10.x
• I've ensured my code works on Python 3.11.x

Checklist

• I've run the pre-commit code linter over all edited files
• I've tested my changes on supported Python versions
• I've added tests for my code, if applicable
• I've updated / added documentation, where applicable