Revert "Bump PySide 6.9.3 to 6.12, requires settings reset (#1511)"

This reverts commit b6a75b3be6.

kindlecomicconverter/KCC_gui.py

@@ -1503,7 +1503,7 @@ class KCCGUI(QObject, KCC_ui.Ui_mainWindow):
         APP = kccapp
         MW = kccwindow
         GUI = self
-        settings_key = 'kcc13'
+        settings_key = 'kcc10'
         if Version(qVersion()) <= Version('6.4.3'):
             settings_key += '-legacy'
         self.settings = QSettings('ciromattia', settings_key)

requirements.txt

@@ -1,4 +1,5 @@
-PySide6
+PySide6; platform_system != 'Windows'
+PySide6<6.10; platform_system == 'Windows'
 Pillow>=11.3.0
 psutil>=7.2.2
 requests>=2.34.2