fix build

Author: nihui

.github/workflows/release.yml

@@ -947,7 +947,7 @@ jobs:
 
         # workaround ar @list issue on macos
         cd modules/world
-        /Applications/Xcode_12.2.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ar qc ../../lib/libopencv_world.a `cat world_objects.rsp` CMakeFiles/opencv_world.dir/src/world_init.cpp.o
+        /Applications/Xcode_12.4.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ar qc ../../lib/libopencv_world.a `cat world_objects.rsp` CMakeFiles/opencv_world.dir/src/world_init.cpp.o
         cd ../..
 
         cmake --build . --target install
@@ -962,7 +962,7 @@ jobs:
 
         # workaround ar @list issue on macos
         cd modules/world
-        /Applications/Xcode_12.2.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ar qc ../../lib/libopencv_world.a `cat world_objects.rsp` CMakeFiles/opencv_world.dir/src/world_init.cpp.o
+        /Applications/Xcode_12.4.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ar qc ../../lib/libopencv_world.a `cat world_objects.rsp` CMakeFiles/opencv_world.dir/src/world_init.cpp.o
         cd ../..
 
         cmake --build . --target install