Bump restrictedpython from 7.1 to 7.3

Bumps [restrictedpython](https://github.com/zopefoundation/RestrictedPython) from 7.1 to 7.3.
- [Changelog](https://github.com/zopefoundation/RestrictedPython/blob/master/CHANGES.rst)
- [Commits](zopefoundation/RestrictedPython@7.1...7.3)

---
updated-dependencies:
- dependency-name: restrictedpython
  dependency-type: direct:production
...

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