fix: account for new pink default avatar

[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 accounts for a new pink default avatar that Discord has added during the username change. Proof of this can be seen in the merged username PR (note the % 6 for user IDs) and the fact that this image now exists.

Changes

• Mod the bitshift of the ID by 6, not 5, when determining which version of the default avatar to use.

Related Issues

Test Scenarios

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