composer(deps-dev): bump orchestra/testbench-core from 8.30.0 to 8.31.0

Bumps [orchestra/testbench-core](https://github.com/orchestral/testbench-core) from 8.30.0 to 8.31.0.
- [Release notes](https://github.com/orchestral/testbench-core/releases)
- [Changelog](https://github.com/orchestral/testbench-core/blob/9.x/CHANGELOG-8.x.md)
- [Commits](orchestral/testbench-core@v8.30.0...v8.31.0)

---
updated-dependencies:
- dependency-name: orchestra/testbench-core
  dependency-type: indirect
  update-type: version-update:semver-minor
...

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