Bump yapf from 0.30.0 to 0.31.0 in /requirements
Bump yapf from 0.30.0 to 0.31.0 in /requirements

Bumps [yapf](https://github.com/google/yapf) from 0.30.0 to 0.31.0.
- [Release notes](https://github.com/google/yapf/releases)
- [Changelog](https://github.com/google/yapf/blob/main/CHANGELOG)
- [Commits](https://github.com/google/yapf/compare/v0.30.0...v0.31.0)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>
dimagi/commcare-hq,dimagi/commcare-hq,dimagi/commcare-hq,dimagi/commcare-hq,dimagi/commcare-hq