build(deps): bump wiremock from 0.5.18 to 0.5.21

Bumps [wiremock](https://github.com/LukeMathWalker/wiremock-rs) from 0.5.18 to 0.5.21.
- [Changelog](https://github.com/LukeMathWalker/wiremock-rs/blob/main/CHANGELOG.md)
- [Commits](LukeMathWalker/wiremock-rs@v0.5.18...v0.5.21)

---
updated-dependencies:
- dependency-name: wiremock
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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