PostWe've just released v20.0a6.

We've just released v20.0a6. Thank you to everyone who contributed to this release. If you want to upgrade from v20.0a5 to v20.0a6, please upgrade with pip install -U --pre python-telegram-bot. Before upgrading from v13.x to v20.0a6, please carefully read the v20.0a0 release notes. This is a bug fix release that addresses some issues of the previous release v20.0a5. In particular, the download methods of telegram.File are now actually named as originally announced. For the full list of changes and improvements, please see below. Bug Fixes • Only Persist Arbitrary callback_data if ExtBot.callback_data_cache is Present (#3384) • Improve Backwards Compatibility of TelegramObjects Pickle Behavior (#3382) • Fix Naming and Keyword Arguments of File.download_* Methods (#3380) • Fix Return Value Annotation of Chat.create_forum_topic (#3381)