multimedia/vapoursynth: Update to R63

• Plugins are no longer maintained within the main project repo
• Revert upstream commit 1239124c2d70f32c468326e48bfa7e9362550c36 as it breaks compatibility with Clang/LLVM with libc++ [1]

1: https://github.com/vapoursynth/vapoursynth/pull/953

Changelog: https://github.com/vapoursynth/vapoursynth/releases/tag/R63