Composer Dev(deps-dev): Bump wp-phpunit/wp-phpunit from 6.2.2 to 6.3.0

Bumps [wp-phpunit/wp-phpunit](https://github.com/wp-phpunit/wp-phpunit) from 6.2.2 to 6.3.0.
- [Commits](wp-phpunit/wp-phpunit@6.2.2...6.3.0)

---
updated-dependencies:
- dependency-name: wp-phpunit/wp-phpunit
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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