Bump python-telegram-bot from 13.15 to 20.2

Bumps [python-telegram-bot](https://github.com/python-telegram-bot/python-telegram-bot) from 13.15 to 20.2.
- [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/v13.15...v20.2)

---
updated-dependencies:
- dependency-name: python-telegram-bot
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

requirements.txt

@@ -6,7 +6,7 @@ ccxt==3.0.59
 cryptography==40.0.1
 aiohttp==3.8.4
 SQLAlchemy==2.0.9
-python-telegram-bot==13.15
+python-telegram-bot==20.2
 arrow==1.2.3
 cachetools==4.2.2
 requests==2.28.2