Install all the prebuilt dependencies for Windows to a specific folder,
and use meson command line options to specify their location.
This removes crossbuild-specific code from the meson scripts and will
simplify dependency upgrades.
PR #4460 <https://github.com/Genymobile/scrcpy/pull/4460>
On the scrcpy-deps repo, I built FFmpeg 5.1.2 binaries for Windows with
only the features used by scrcpy.
For comparison, here are the sizes of the dll for FFmpeg 5.1.2:
- before: 89M
- after: 4.7M
It also allows to upgrade the old FFmpeg version (4.3.1) used for win32.
Refs <https://github.com/rom1v/scrcpy-deps>
Refs <https://github.com/Genymobile/scrcpy/issues/1753>
