build(deps): bump plank/laravel-mediable from 6.1.2 to 6.1.3 (#849)

Bumps [plank/laravel-mediable](https://github.com/plank/laravel-mediable) from 6.1.2 to 6.1.3.
- [Release notes](https://github.com/plank/laravel-mediable/releases)
- [Changelog](https://github.com/plank/laravel-mediable/blob/master/CHANGELOG.md)
- [Commits](plank/laravel-mediable@6.1.2...6.1.3)

---
updated-dependencies:
- dependency-name: plank/laravel-mediable
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>