Revert "Link OpenMW with libz on macOS"

This reverts commit 0c4dd05118.

CI/before_script.osx.sh

@@ -10,6 +10,7 @@ mkdir build
 cd build
 
 cmake \
+-D CMAKE_EXE_LINKER_FLAGS="-lz" \
 -D CMAKE_PREFIX_PATH="$DEPENDENCIES_ROOT;$QT_PATH" \
 -D CMAKE_OSX_DEPLOYMENT_TARGET="10.8" \
 -D CMAKE_OSX_SYSROOT="macosx10.11" \

apps/openmw/CMakeLists.txt

@@ -181,7 +181,7 @@ endif()
 if(APPLE)
     find_library(COCOA_FRAMEWORK Cocoa)
     find_library(IOKIT_FRAMEWORK IOKit)
-    target_link_libraries(openmw z ${COCOA_FRAMEWORK} ${IOKIT_FRAMEWORK})
+    target_link_libraries(openmw ${COCOA_FRAMEWORK} ${IOKIT_FRAMEWORK})
 
     if (FFmpeg_FOUND)
         find_library(COREVIDEO_FRAMEWORK CoreVideo)