Bump @wdio/cli from 8.15.5 to 8.15.9

Bumps [@wdio/cli](https://github.com/webdriverio/webdriverio/tree/HEAD/packages/wdio-cli) from 8.15.5 to 8.15.9.
- [Release notes](https://github.com/webdriverio/webdriverio/releases)
- [Changelog](https://github.com/webdriverio/webdriverio/blob/main/CHANGELOG.md)
- [Commits](https://github.com/webdriverio/webdriverio/commits/v8.15.9/packages/wdio-cli)

---
updated-dependencies:
- dependency-name: "@wdio/cli"
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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