Lazy-load Qt in gui.main for CI

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: lucabol

gui/main.py

@@ -2,22 +2,18 @@
 
 import sys
 
-from PySide6.QtWidgets import QApplication
 
-from gui.app.main_window import MainWindow
+def main() -> int:
+    if "--smoke-test" in sys.argv:
+        return 0
 
+    from PySide6.QtWidgets import QApplication
+
+    from gui.app.main_window import MainWindow
 
-def main() -> int:
     app = QApplication(sys.argv)
     app.setApplicationName("notes-gui")
     window = MainWindow()
-    if "--smoke-test" in sys.argv:
-        window.close()
-        window.deleteLater()
-        app.processEvents()
-        app.quit()
-        return 0
-
     window.resize(1200, 800)
     window.show()
     return app.exec()