Bump nextcloud-vue from 0.12.4 to 0.12.6

Bumps [nextcloud-vue](https://github.com/nextcloud/nextcloud-vue) from 0.12.4 to 0.12.6.
- [Release notes](https://github.com/nextcloud/nextcloud-vue/releases)
- [Commits](https://github.com/nextcloud/nextcloud-vue/compare/v0.12.4...v0.12.6

)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>