Notable changes:
* Windows: Add Qt 5 and 6 builds
* Windows: Remove nasm native build
* Windows: Update srt from 1.4.2 to 1.4.4
* Windows: Update SWIG from 3.0.12 to 4.1.0-git
* macOS: Update libvpx from 1.10.0 to 1.11.0
* macOS: Update srt from 1.4.1 to 1.4.4
* macOS: Update SWIG from 3.0.12 to 4.1.0-git
* macOS: Update x264 from r3059 to r3060