duplicate symbol qLcNav

The linker gives me a warning:

ld: warning: duplicate symbol 'qLcNav()' in:
    /Users/rutledge/dev/qt6-ios/qtbase/lib/libQt6PdfQuick_debug.a(qquickpdfpagenavigator.cpp.o)
    /Users/rutledge/dev/qt6-ios/qtbase/lib/libQt6Pdf_debug.a(qpdfpagenavigator.cpp.o)

I think it's because it's a static build on iOS. I haven't noticed when using dynamic linking: the Quick plugin loads the QtPDF C++ module and doesn't complain. But I guess we could use two different logging categories to get rid of this, if switching to Q_DECLARE_LOGGING_CATEGORY doesn't work.