Bump libwebp to v1.4.0 (#2133)

diff --git a/cmake/Modules/LocalLibsharpyuv.cmake b/cmake/Modules/LocalLibsharpyuv.cmake
index 7898f00..99554e5 100644
--- a/cmake/Modules/LocalLibsharpyuv.cmake
+++ b/cmake/Modules/LocalLibsharpyuv.cmake
@@ -1,4 +1,4 @@
-set(AVIF_LOCAL_LIBSHARPYUV_GIT_TAG v1.3.2)
+set(AVIF_LOCAL_LIBSHARPYUV_GIT_TAG v1.4.0)
 
 set(LIB_FILENAME "${CMAKE_CURRENT_SOURCE_DIR}/ext/libwebp/build/libsharpyuv${CMAKE_STATIC_LIBRARY_SUFFIX}")
 if(EXISTS "${LIB_FILENAME}")
diff --git a/ext/libsharpyuv.cmd b/ext/libsharpyuv.cmd
index 0e05410..380c92a 100755
--- a/ext/libsharpyuv.cmd
+++ b/ext/libsharpyuv.cmd
@@ -9,11 +9,9 @@
 : #     "C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\VC\Auxiliary\Build\vcvars64.bat"
 
 : # libsharpyuv is part of the libwebp repo.
-git clone --single-branch https://chromium.googlesource.com/webm/libwebp
+git clone -b v1.4.0 --depth 1 https://chromium.googlesource.com/webm/libwebp
 
 cd libwebp
-git checkout e2c85878f6a33f29948b43d3492d9cdaf801aa54
-
 mkdir build
 cd build
 cmake -G Ninja -DBUILD_SHARED_LIBS=OFF -DCMAKE_BUILD_TYPE=Release -DWEBP_BUILD_ANIM_UTILS=OFF -DWEBP_BUILD_CWEBP=OFF -DWEBP_BUILD_DWEBP=OFF -DWEBP_BUILD_GIF2WEBP=OFF -DWEBP_BUILD_IMG2WEBP=OFF -DWEBP_BUILD_VWEBP=OFF -DWEBP_BUILD_WEBPINFO=OFF -DWEBP_BUILD_LIBWEBPMUX=OFF -DWEBP_BUILD_WEBPMUX=OFF -DWEBP_BUILD_EXTRAS=OFF  ..