Upgrade to Django 6

[geekygirlsarah]

What GitHub issue does this PR apply to?

N/A

What changed and why?

Upgrade Django from 4 to 6

AI bots used in the process of making this PR

Junie

(If editing website code) Please add screenshots

Checklist

• I claimed any associated issue(s) and they are not someone else's
• I have looked at documentation to ensure I made any revisions correctly
• I tested my changes locally to ensure they work
• For language files, I have validated the edited files are valid JSON and data shows up correctly
• For website code edits, I have added or edited any appropriate unit tests for my changes
• If I used artificial intelligence (AI), I have reviewed the suggested changes and ensured they work correctly

Any additional comments or things to be aware of while reviewing?