Bump wiremock from 0.5.7 to 0.5.8 in /src/agent (#1414)

Bumps [wiremock](https://github.com/LukeMathWalker/wiremock-rs) from 0.5.7 to 0.5.8.
- [Release notes](https://github.com/LukeMathWalker/wiremock-rs/releases)
- [Changelog](https://github.com/LukeMathWalker/wiremock-rs/blob/main/CHANGELOG.md)
- [Commits](LukeMathWalker/wiremock-rs@v0.5.7...v0.5.8)

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

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Marc Greisen <marc@greisen.org>