Bump python-telegram-bot from 12.7 to 12.8

Bumps [python-telegram-bot](https://github.com/python-telegram-bot/python-telegram-bot) from 12.7 to 12.8.
- [Release notes](https://github.com/python-telegram-bot/python-telegram-bot/releases)
- [Changelog](https://github.com/python-telegram-bot/python-telegram-bot/blob/master/CHANGES.rst)
- [Commits](https://github.com/python-telegram-bot/python-telegram-bot/compare/v12.7...v12.8)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

requirements-common.txt

@@ -2,7 +2,7 @@
 # mainly used for Raspberry pi installs
 ccxt==1.30.34
 SQLAlchemy==1.3.18
-python-telegram-bot==12.7
+python-telegram-bot==12.8
 arrow==0.15.7
 cachetools==4.1.0
 requests==2.24.0