Make sure we don't leak interfaces

Properly set the parent

src/wayland/textinput_v2_interface.cpp

@@ -362,7 +362,7 @@ QList<TextInputV2InterfacePrivate::Resource *> TextInputV2InterfacePrivate::text
 }
 
 TextInputV2Interface::TextInputV2Interface(SeatInterface *seat)
-    : QObject()
+    : QObject(seat)
     , d(new TextInputV2InterfacePrivate(seat, this))
 {
 }

src/wayland/textinput_v3_interface.cpp

@@ -337,7 +337,7 @@ void TextInputV3InterfacePrivate::defaultPending()
 }
 
 TextInputV3Interface::TextInputV3Interface(SeatInterface *seat)
-    : QObject()
+    : QObject(seat)
     , d(new TextInputV3InterfacePrivate(seat, this))
 {
 }