Bump rsa from 4.3 to 4.7

Bumps [rsa](https://github.com/sybrenstuvel/python-rsa) from 4.3 to 4.7.
- [Changelog](https://github.com/sybrenstuvel/python-rsa/blob/main/CHANGELOG.md)
- [Commits](sybrenstuvel/python-rsa@version-4.3...version-4.7)

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

Signed-off-by: dependabot[bot] <[email protected]>

requirements-base.txt

@@ -90,7 +90,7 @@ requests-futures==1.0.0
 requests-mock==1.8.0
 rfc3987==1.3.8
 # rsa is an oauth2client dependency. 4.3 is the last version to support Python 2.
-rsa==4.3
+rsa==4.7
 s3transfer==0.5.2
 singledispatch==3.4.0.3
 snowballstemmer==2.0.0