ECMQmlModule6: group qml and resource file calls

Otherwise we get a different qrc file for each occurrence ending up with
an overly complex call for no reason.

modules/ECMQmlModule6.cmake

@@ -112,6 +112,8 @@ function(ecm_target_qml_sources ARG_TARGET)
         set_source_files_properties(${ARG_SOURCES} PROPERTIES QT_QML_INTERNAL_TYPE TRUE)
     endif()
 
+    set(_QML_FILES)
+    set(_RESOURCES)
     foreach(_path ${ARG_SOURCES})
         get_filename_component(_file "${_path}" NAME)
         get_filename_component(_ext "${_path}" EXT)
@@ -121,11 +123,19 @@ function(ecm_target_qml_sources ARG_TARGET)
         endif()
         set_source_files_properties("${_path}" PROPERTIES QT_RESOURCE_ALIAS "${_resource_alias}")
         if ("${_ext}" MATCHES "(.qml|.js|.mjs)")
-            qt6_target_qml_sources(${ARG_TARGET} QML_FILES "${_path}" ${ARG_UNPARSED_ARGUMENTS})
+            list(APPEND _QML_FILES "${_path}")
         else()
-            qt6_target_qml_sources(${ARG_TARGET} RESOURCES "${_path}" ${ARG_UNPARSED_ARGUMENTS})
+            list(APPEND _RESOURCES "${_path}")
         endif()
     endforeach()
+
+    if(_QML_FILES)
+        qt6_target_qml_sources(${ARG_TARGET} QML_FILES ${_QML_FILES} ${ARG_UNPARSED_ARGUMENTS})
+    endif()
+    if(_RESOURCES)
+        qt6_target_qml_sources(${ARG_TARGET} RESOURCES ${_RESOURCES} ${ARG_UNPARSED_ARGUMENTS})
+    endif()
+
 endfunction()
 
 function(ecm_finalize_qml_module ARG_TARGET)