Bump pact_broker-client from 1.20.0 to 1.22.1
Bump pact_broker-client from 1.20.0 to 1.22.1

Bumps [pact_broker-client](https://github.com/bethesque/pact_broker-client) from 1.20.0 to 1.22.1.
- [Release notes](https://github.com/bethesque/pact_broker-client/releases)
- [Changelog](https://github.com/pact-foundation/pact_broker-client/blob/master/CHANGELOG.md)
- [Commits](https://github.com/bethesque/pact_broker-client/compare/v1.20.0...v1.22.1)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
alphagov/publishing-api,alphagov/publishing-api