This will fetch and call the build_usd.py build helper for OpenUSD and build within the MuJoCo _deps folder. Simplifying the build process for MuJoCo with USD. Users can still provide their own USD build, but must now do so via pxr_DIR.
PiperOrigin-RevId: 846735578
Change-Id: I0da7eb2da6465e2d518084340e762bf370adb6d5
Adds targets for dear_imgui, implot, filament, sdl2, and webp. These
targets are not currently used.
PiperOrigin-RevId: 824554405
Change-Id: Ibebdd50752d251852a945b6abc230e2c6e65fae9