chore(deps): bump pingora from 0.3.0 to 0.4.0

Bumps [pingora](https://github.com/cloudflare/pingora) from 0.3.0 to 0.4.0.
- [Release notes](https://github.com/cloudflare/pingora/releases)
- [Changelog](https://github.com/cloudflare/pingora/blob/main/CHANGELOG.md)
- [Commits](cloudflare/pingora@0.3.0...0.4.0)

---
updated-dependencies:
- dependency-name: pingora
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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