Steps to Reproduce

1. when i run sample conversationbot.py in the offical document, i found it is case-insensitive

Expected behaviour

it should accept input such as boy/Boy/BOY

Actual behaviour

if I type wrong message, the program hang out

Operating System

macos

Version of Python, python-telegram-bot & dependencies

python-telegram-bot 21.5
Bot API 7.9
Python 3.11.5 (main, Aug 24 2023, 15:09:45) [Clang 14.0.3 (clang-1403.0.22.14.1)]

Relevant log output

Additional Context

I found just modify the code, it can fix this bug.
GENDER: [MessageHandler(filters.Regex("^(Boy|Girl|Other)$"), gender)],
to
GENDER: [MessageHandler(filters.Regex("(?i)^(Boy|Girl|Other)$"), gender)].