Bump php-http/mock-client from 1.4.1 to 1.5.0

Bumps [php-http/mock-client](https://github.com/php-http/mock-client) from 1.4.1 to 1.5.0.
- [Release notes](https://github.com/php-http/mock-client/releases)
- [Changelog](https://github.com/php-http/mock-client/blob/master/CHANGELOG.md)
- [Commits](php-http/mock-client@1.4.1...1.5.0)

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

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