Info.plist should set CFBundleDevelopmentRegion to QT_I18N_SOURCE_LANGUAGE

The _qt_internal_set_apple_localizations() command in QtPublicAppleHelpers.cmake makes adjustments to the Info.plist file generated for an app on Apple platforms. It populates the CFBundleLocalizations array from the QT_I18N_TRANSLATED_LANGUAGES variable, but it should probably also set CFBundleDevelopmentRegion to the value of the QT_I18N_SOURCE_LANGUAGE variable too.

Also see QTBUG-63324 for some relevant background.