Enable MuJoCo Studio build and packaging on macos.

Also:
- Packages MuJoCo Studio as MuJoCoStudio.app in the MuJoCo.dmg.
- Fixes a Filament compile issue.
- Patches libwebp to fix compile error related to universal builds and forces
  it to build as static.
- Removes the separate, obsolete "build_studio" step.
PiperOrigin-RevId: 934564785
Change-Id: I50c83283b5e138062e37d53926a5a77fdf99dbfa

cmake/third_party_deps/filament.cmake

@@ -32,6 +32,11 @@ else()
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -include cstring -include optional")
 endif()
 
+# Filament generates deprecated warnings on MacOS.
+if(CMAKE_SYSTEM_NAME STREQUAL "Darwin")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-error=deprecated-declarations")
+endif()
+
 set(FILAMENT_ENABLE_EXPERIMENTAL_GCC_SUPPORT ON)
 set(FILAMENT_SKIP_SDL2 ON)
 set(FILAMENT_USE_EXTERNAL_ABSL ON)