Bump python-telegram-bot from 20.6 to 20.7 (#432)

Bumps [python-telegram-bot](https://github.com/python-telegram-bot/python-telegram-bot) from 20.6 to 20.7.
- [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](python-telegram-bot/python-telegram-bot@v20.6...v20.7)

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

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