chore(deps-dev): bump php-http/mock-client from 1.6.0 to 1.6.1

Bumps [php-http/mock-client](https://github.com/php-http/mock-client) from 1.6.0 to 1.6.1.
- [Release notes](https://github.com/php-http/mock-client/releases)
- [Changelog](https://github.com/php-http/mock-client/blob/1.x/CHANGELOG.md)
- [Commits](php-http/mock-client@1.6.0...1.6.1)

---
updated-dependencies:
- dependency-name: php-http/mock-client
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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