Bump cdav-library from `79dee27` to `9260de5`

Bumps [cdav-library](https://github.com/nextcloud/cdav-library) from `79dee27` to `9260de5`.
- [Release notes](https://github.com/nextcloud/cdav-library/releases)
- [Commits](https://github.com/nextcloud/cdav-library/compare/79dee27bc92bf3b6ece57fb6097d602ce574612a...9260de57f978774ba3db515f5a17aa28be543a56

)

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