Package has dependency to OpenTK v4.3.0 only

Hi, 

Thanks a lot for the library. Would it be possible to make this package compatible with the latest OpenTK version (v4.6.7 as time of writting). 

Current dependency is setup as `OpenTK (>= 4.3.0 && <4.4.0)`, I guess making it `OpenTK (>= 4.3.0)` would fix that.

Thanks a lot! 