Update asttokens requirement from ~=2.1.0 to ~=2.2.0

Updates the requirements on [asttokens](https://github.com/gristlabs/asttokens) to permit the latest version.
- [Release notes](https://github.com/gristlabs/asttokens/releases)
- [Commits](gristlabs/asttokens@2.1.0...2.2.0)

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

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

requirements.txt

@@ -7,7 +7,7 @@
 alabaster==0.7.12
 argon2-cffi~=21.3.0
 argon2-cffi-bindings~=21.2.0
-asttokens~=2.1.0
+asttokens~=2.2.0
 attrs~=22.1.0
 autodocsumm==0.2.9
 azure-core~=1.26.0