## Description
Uses the newer version of `wholphin-extensions` which now has the Kotlin
code, so this PR removes the MPV Kotlin code from this repo. Also
updates gradle to use providers.
There are no user facing changes
### Dev notes
`wholphin-mpv` can be provided by:
1. [Fetching pre-built
binaries](https://github.com/damontecres/wholphin-extensions#pre-built-binaries)
(Preferred method for devs)
2. Building `wholphin-extensions` from
[source](https://github.com/damontecres/wholphin-extensions#build-from-source)
3. Using `wholphin-mpv-stub` (the new module added in this PR) which
allows for compiling Wholphin, but will throw exceptions if MPV is used
during runtime
### Related issues
Related to #1172
### Testing
Emulator
## Screenshots
N/A
## AI or LLM usage
None
