Enable Metal and Accelerate features for Apple platforms in Candle module

- Uncomment Apple-specific CMake configuration for Candle
- Add Metal and Accelerate features when building on macOS
- Provide option to disable Metal support via DISABLE_CANDLE_METAL flag

Author: sinkingsugar

Diff for: shards/modules/candle/CMakeLists.txt

@@ -1,10 +1,10 @@
 # Platform-specific features
-# if(APPLE)
-#   if(NOT DISABLE_CANDLE_METAL)
-#     list(APPEND ML_RUST_FEATURES "metal") # In reality this will only work on macOS unless metal is initialized before (e.g. Formabble app)
-#   endif()
-#   list(APPEND ML_RUST_FEATURES "accelerate")
-# endif()
+if(APPLE)
+  if(NOT DISABLE_CANDLE_METAL)
+    list(APPEND ML_RUST_FEATURES "metal") # In reality this will only work on macOS unless metal is initialized before (e.g. Formabble app)
+  endif()
+  list(APPEND ML_RUST_FEATURES "accelerate")
+endif()
 
 # Add an option to enable or disable CUDA support
 option(ENABLE_CUDA "Enable CUDA support" OFF)