Build failure with kpimtextedit built w/o Qt5TextToSpeech

Qt5TextToSpeech is optional in >=22.04, mostly because it is not available in Qt6 yet, but kjots fails to build in this case.

kjots-5.1.0/src/kjotsbrowser.cpp:30:10: fatal error: KPIMTextEdit/TextToSpeechWidget: No such file or directory
   30 | #include <KPIMTextEdit/TextToSpeechWidget>
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Dependency introduced in !1 (merged)