Ensure dynamic libjpeg libraries are not linked (#9081)

Author: hugovk

.github/workflows/wheels-dependencies.sh

@@ -60,7 +60,7 @@ if [[ "$CIBW_PLATFORM" == "ios" ]]; then
     # on using the Xcode builder, which isn't very helpful for most of Pillow's
     # dependencies. Therefore, we lean on the OSX configurations, plus CC, CFLAGS
     # etc. to ensure the right sysroot is selected.
-    HOST_CMAKE_FLAGS="-DCMAKE_SYSTEM_NAME=$CMAKE_SYSTEM_NAME -DCMAKE_SYSTEM_PROCESSOR=$GNU_ARCH -DCMAKE_OSX_DEPLOYMENT_TARGET=$IPHONEOS_DEPLOYMENT_TARGET -DCMAKE_OSX_SYSROOT=$IOS_SDK_PATH -DBUILD_SHARED_LIBS=NO"
+    HOST_CMAKE_FLAGS="-DCMAKE_SYSTEM_NAME=$CMAKE_SYSTEM_NAME -DCMAKE_SYSTEM_PROCESSOR=$GNU_ARCH -DCMAKE_OSX_DEPLOYMENT_TARGET=$IPHONEOS_DEPLOYMENT_TARGET -DCMAKE_OSX_SYSROOT=$IOS_SDK_PATH -DBUILD_SHARED_LIBS=NO -DENABLE_SHARED=NO"
 
     # Meson needs to be pointed at a cross-platform configuration file
     # This will be generated once CC etc. have been evaluated.
@@ -380,6 +380,15 @@ fi
 
 wrap_wheel_builder build
 
+# A safety catch for iOS. iOS can't use dynamic libraries, but clang will prefer
+# to link dynamic libraries to static libraries. The only way to reliably
+# prevent this is to not have dynamic libraries available in the first place.
+# The build process *shouldn't* generate any dylibs... but just in case, purge
+# any dylibs that *have* been installed into the build prefix directory.
+if [[ -n "$IOS_SDK" ]]; then
+    find "$BUILD_PREFIX" -name "*.dylib" -exec rm -rf {} \;
+fi
+
 # Return to the project root to finish the build
 popd > /dev/null