⚡ Add true asyncio support

[Ousret]

3.5.0 (2024-02-28)

Changed

• Replaced the thread pool executor for the true asyncio implementation. The asynchronous part is rewritten.
• urllib3.future lower bound constraint has been raised to version 2.6.900 for the newly added asynchronous interfaces.

Added

• Support for awaitable hooks in AsyncSession.
• Extendable AsyncBaseAdapter.
• Support for orjson if installed in environment to dramatically increase performance in JSON deserialization.
• Extra speedups to increase overall performances by including optional dependencies such as zstandard, brotli and orjson.

Fixed

• A rare error when leveraging multiplexing when a proxy is used.
• Bypass proxies when looking to validate certificate revocation status in Python < 3.10 with OCSP.

[Ousret]

Seems like PyPy doesn't implement the Windows Socket API in full.
PyPy + Windows + Asyncio = No HTTP/3 support available until further info.