v0.20.0

• Dropped Python 3.8 support.
• Breaking change (.state_store) Removed legacy SQLAlchemy state store implementations.
• Mildly breaking change (util.async_db) Changed SQLiteDatabase to not remove prefix slashes from database paths.
  • Library users should use sqlite:path.db instead of sqlite:///path.db for relative paths, and sqlite:/path.db instead of sqlite:////path.db for absolute paths.
  • Bridge configs do this migration automatically.
• (util.async_db) Added warning log if using SQLite database path that isn't writable.
• (util.program) Fixed manual_stop not working if it's called during startup.
• (client) Stabilized support for asynchronous uploads.
  • unstable_create_msc was renamed to create_mxc, and the max_stall_ms parameters for downloading were renamed to timeout_ms.
• (crypto) Added option to not rotate keys when devices change.
• (crypto) Added option to remove all keys that were received before the automatic ratcheting was implemented (in v0.19.10).
• (types) Improved reply fallback removal to have a smaller chance of false positives for messages that don't use reply fallbacks.