Bump mini_racer from 0.4.0 to 0.6.1
Bump mini_racer from 0.4.0 to 0.6.1

Bumps [mini_racer](https://github.com/discourse/mini_racer) from 0.4.0 to 0.6.1.
- [Release notes](https://github.com/discourse/mini_racer/releases)
- [Changelog](https://github.com/rubyjs/mini_racer/blob/master/CHANGELOG)
- [Commits](https://github.com/discourse/mini_racer/compare/v0.4.0...v0.6.1)

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

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>
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