Fix tests to build in a no-widgets configuration

The qfilesystemmodel.pro was recently moved to the gui tests subfolder,
but it uses widgets inside. Skip it in a no-widgets build.

Amends fb9ec8ad44

Task-number: QTBUG-86187
Change-Id: I955556ffddad483d4c25602ae126b8c2433091b2
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

tests/auto/gui/itemmodels/CMakeLists.txt

@@ -1,9 +1,9 @@
 # Generated from itemmodels.pro.
 
 add_subdirectory(qstandarditem)
-if(NOT MINGW)
-    add_subdirectory(qfilesystemmodel)
-endif()
 if(TARGET Qt::Widgets)
     add_subdirectory(qstandarditemmodel)
 endif()
+if(TARGET Qt::Widgets AND NOT MINGW)
+    add_subdirectory(qfilesystemmodel)
+endif()

tests/auto/gui/itemmodels/itemmodels.pro

@@ -6,5 +6,8 @@ SUBDIRS= \
 
 mingw: SUBDIRS -= qfilesystemmodel # QTBUG-29403
 
-!qtHaveModule(widgets): SUBDIRS -= \
+!qtHaveModule(widgets) {
+    SUBDIRS -= \
+        qfilesystemmodel \
         qstandarditemmodel
+}