CMake: Add homebrew llvm to the find_package paths

Because llvm overrides packages that are provided by macOS system
packages, homebrew goes out of its way to avoid letting them be default
findable. Adding this extra search path avoids having to pass a
CMAKE_PREFIX_PATH or CMAKE_MODULE_PATH argument when using brew llvm.

CMakeLists.txt

@@ -24,7 +24,9 @@ find_package(Threads REQUIRED)
 
 SET(CMAKE_FIND_PACKAGE_SORT_ORDER NATURAL)
 SET(CMAKE_FIND_PACKAGE_SORT_DIRECTION DEC)
-find_package(Clang CONFIG)
+find_package(Clang CONFIG
+  PATHS /opt/homebrew/opt/llvm
+)
 
 set(JAKT_CPP_AUTO_IMPORT_PROCESSOR_DEFAULT none)
 if (Clang_FOUND)