feat(python): Update docs for SDK 2.0

[sentrivana]

Pre-merge checklist

If you work at Sentry, you're able to merge your own PR without review, but please don't unless there's a good reason.

• [x] Checked Vercel preview for correctness, including links
• [ ] PR was reviewed and approved by any necessary SMEs
• [ ] PR was reviewed and approved by a member of the Sentry docs team

Description of changes

We'll be releasing the 2.0 version of the Python SDK soon. Updating the docs to reflect this:

• update supported versions of frameworks and Python on integration pages
• add a note about getting support for older (now dropped) Python/framework versions to each affected integration page
• add a note about migrating from 1.x to 2.x to the Python landing page
• update the list of auto-enabling integrations
• remove previously deprecated -- and now removed -- configuration options
• warn about newly deprecated options (profiler)
• remove mentions of Hub

Fixes https://github.com/getsentry/sentry-python/issues/2665

NOT READY TO BE MERGED: Release not out yet.