[23.08] Build broken without precompiled headers

It seems that build of apps/lib directory is currently broken without precompiled headers.

Downstream report with log: https://bugs.gentoo.org/921720

I can reproduce the problem with -DBUILD_PCH=OFF.

Adding author of commit dd6e1870 (!1149 (merged)).

In file included from apps/lib/ktexteditor_utils.cpp:7:
apps/lib/ktexteditor_utils.h:97:21: error: ‘QWidgetList’ does not name a type; did you mean ‘QWidget’?
   97 | KATE_PRIVATE_EXPORT QWidgetList widgets(KTextEditor::MainWindow *mainWindow);
      |                     ^~~~~~~~~~~
      |                     QWidget
apps/lib/ktexteditor_utils.h:101:53: error: ‘QUrl’ does not name a type
  101 | KATE_PRIVATE_EXPORT void addPositionToHistory(const QUrl &url, KTextEditor::Cursor c, KTextEditor::MainWindow *mainWindow);
      |                                                     ^~~~

New error in addons/project:

In file included from addons/project/kateprojectworker.h:10,
                 from addons/project/kateprojectworker.cpp:8:
addons/project/kateproject.h:10:5: warning: "QT_VERSION" is not defined, evaluates to 0 [-Wundef]
   10 | #if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
      |     ^~~~~~~~~~
addons/project/kateproject.h:10:18: warning: "QT_VERSION_CHECK" is not defined, evaluates to 0 [-Wundef]
   10 | #if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
      |                  ^~~~~~~~~~~~~~~~
addons/project/kateproject.h:10:34: error: missing binary operator before token "("
   10 | #if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
      |                                  ^
addons/project/kateproject.h:279:92: error: ‘KTextEditor::ModificationInterface’ has not been declared
  279 |     void slotModifiedOnDisk(KTextEditor::Document *document, bool isModified, KTextEditor::ModificationInterface::ModifiedOnDiskReason reason);
      |                                                                                            ^~~~~~~~~~~~~~~~~~~~~
addons/project/kateproject.h:279:136: error: expected ‘,’ or ‘...’ before ‘reason’
  279 |     void slotModifiedOnDisk(KTextEditor::Document *document, bool isModified, KTextEditor::ModificationInterface::ModifiedOnDiskReason reason);
      |                                                                                                                                        ^~~~~~