ci: sweep remaining QLatin1String::toUtf8; embed version obj in oakengine.dll

- pointer.cpp/transition.cpp: same Qt 6.4 incompatibility as import.cpp
- Windows: DLLs cannot have undefined symbols, so the
  executable-provides-k_app_version trick does not link; embed
  olive-version-obj into oakengine on WIN32 (each module keeps its own
  copy)

engine/CMakeLists.txt

@@ -55,6 +55,13 @@ add_library(oakengine-obj OBJECT
 
 add_library(oakengine SHARED $<TARGET_OBJECTS:oakengine-obj>)
 
+if (WIN32)
+  # Windows DLLs cannot have undefined symbols; embed the version objects
+  # here too (each module keeps its own copy, unlike ELF where the final
+  # executable provides the definition).
+  target_sources(oakengine PRIVATE $<TARGET_OBJECTS:olive-version-obj>)
+endif ()
+
 if (COMMAND oak_copy_otio_runtime)
   oak_copy_otio_runtime(oakengine)
 endif()