chore: update CMake dependency configurations to remove PARENT_SCOPE

- Removed PARENT_SCOPE from various dependency target definitions in CMake files (grpc.cmake, imgui.cmake, sdl2.cmake, testing.cmake, yaml.cmake).
- Ensured that all targets are set locally for better clarity and management.

Benefits:
- Simplifies the dependency management process and improves the readability of CMake configurations.

cmake/dependencies/imgui.cmake

@@ -67,7 +67,6 @@ if(YAZE_BUILD_TESTS)
 endif()
 
 # Export ImGui targets for use in other CMake files  
-set(YAZE_IMGUI_TARGETS ImGui PARENT_SCOPE)
 set(YAZE_IMGUI_TARGETS ImGui)
 
 message(STATUS "Dear ImGui setup complete - YAZE_IMGUI_TARGETS = ${YAZE_IMGUI_TARGETS}")