CMake: Clarify qt_record_extra_third_party_dependency docs

Pick-to: 6.4
Change-Id: I458a5b488741c639650c8b3b6668c82c80b5e93f
Reviewed-by: Alexey Edelev <alexey.edelev@qt.io>
Reviewed-by: Jörg Bornemann <joerg.bornemann@qt.io>

cmake/QtFindPackageHelpers.cmake

@@ -284,6 +284,8 @@ endfunction()
 # Needed to record a dependency on the package that provides WrapVulkanHeaders::WrapVulkanHeaders.
 # The package version, components, whether the package is optional, etc, are queried from the
 # ${dep_target} target properties.
+# Usually these are set at the qt_find_package() call site of a configure.cmake file e.g. using
+# Qt's MARK_OPTIONAL option.
 function(qt_record_extra_third_party_dependency main_target_name dep_target)
     if(NOT TARGET "${main_target_name}")
         qt_get_tool_target_name(main_target_name "${main_target_name}")

cmake/QtTargetHelpers.cmake

@@ -850,7 +850,7 @@ endfunction()
 # To achieve that, consumers of ${target} will only get the include directories of ${dep_target}
 # if the latter package and target exists.
 #
-# A find_package(dep_target) dependency is added to ${target}'s ModuleDependencies.cmake file.
+# A find_package(dep_target) dependency is added to ${target}'s *Dependencies.cmake file.
 #
 # We use target_include_directories(PRIVATE) instead of target_link_libraries(PRIVATE) because the
 # latter would propagate a mandatory LINK_ONLY dependency on the ${dep_target} in a static Qt build.