Fix: Add missing NGL_TARGET_LINK_DIRECTORIES macro

- Added NGL_TARGET_LINK_DIRECTORIES macro to NGLMacros.cmake
- Required for BUILD_RTI=ON configuration
- Follows pattern of existing NGL_TARGET_* macros

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

qt6-after/qt6-migrated-legatus/cmake/NGLMacros.cmake

@@ -336,6 +336,14 @@ MACRO(NGL_TARGET_INCLUDE_DIRECTORIES _target_NAME)
 
 ENDMACRO()
 
+MACRO(NGL_TARGET_LINK_DIRECTORIES _target_NAME)
+
+  IF(TARGET ${_target_NAME})
+    TARGET_LINK_DIRECTORIES(${_target_NAME} ${ARGN})
+  ENDIF()
+
+ENDMACRO()
+