feat: add premium buttons

[AstreaTSS]

Pull Request Type

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

Description

Discord added a premium upsell button style for components. This PR adds them and notes the deprecation of the PREMIUM_REQUIRED response (noted in the changelog linked).

Changes

• Add PREMIUM = 6 to ButtonStyles.
• Added sku_id to Button.
  • Checks were also adjusted or added to note the presence of it.

Related Issues

Resolves #1702.

Test Scenarios

import interactions as ipy

@ipy.slash_command("test", description="test!")
async def test(ctx: ipy.SlashContext):
    button = ipy.Button(style=ipy.ButtonStyle.PREMIUM, sku_id="SKU_ID")
    await ctx.send("test!", components=[button])

Python Compatibility

• I've ensured my code works on Python 3.10.x - kind of? I can't test the button sending, but I do get the correct errors, so...
• 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