py-urllib3: updated to 1.25.10

1.25.10

* Added support for ``SSLKEYLOGFILE`` environment variable for
  logging TLS session keys with use with programs like
  Wireshark for decrypting captured web traffic

* Fixed loading of SecureTransport libraries on macOS Big Sur
  due to the new dynamic linker cache

* Collapse chunked request bodies data and framing into one
  call to ``send()`` to reduce the number of TCP packets by 2-4x

* Don't insert ``None`` into ``ConnectionPool`` if the pool
  was empty when requesting a connection

* Avoid ``hasattr`` call in ``BrotliDecoder.decompress()``

(adam)