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/libwebp.cmake

@@ -20,9 +20,21 @@ mark_as_advanced(MUJOCO_DEP_VERSION_libwebp)
 
 include(FindOrFetch)
 
+set(LIBWEBP_PATCH_COMMAND
+  git apply --reject --whitespace=fix ${mujoco_SOURCE_DIR}/cmake/libwebp-apple-float16.patch
+)
+
+set(BUILD_SHARED_LIBS_OLD ${BUILD_SHARED_LIBS})
+set(BUILD_SHARED_LIBS OFF)
+
 fetchpackage(
     PACKAGE_NAME  libwebp
     GIT_REPO      https://github.com/webmproject/libwebp.git
     GIT_TAG       ${MUJOCO_DEP_VERSION_libwebp}
     TARGETS       webp
+    PATCH_COMMAND ${LIBWEBP_PATCH_COMMAND}
 )
+
+set(BUILD_SHARED_LIBS ${BUILD_SHARED_LIBS_OLD})
+
+