Bump christophwurst/nextcloud_testing from 0.12.3 to 0.12.4

Bumps [christophwurst/nextcloud_testing](https://github.com/ChristophWurst/nextcloud_testing) from 0.12.3 to 0.12.4.
- [Release notes](https://github.com/ChristophWurst/nextcloud_testing/releases)
- [Commits](https://github.com/ChristophWurst/nextcloud_testing/compare/v0.12.3...v0.12.4

)

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