installer.py: Avoid listing beta installers and warn 13.0 builds

gui/gui_main.py

@@ -1495,6 +1495,17 @@ class wx_python_gui:
         self.grab_installer_data(ias=ias)
 
     def download_macos_click(self, app_dict):
+
+        try:
+            app_major = app_dict['Version'].split(".")[0]
+            if float(app_major) > self.constants.os_support:
+                # Throw pop up warning OCLP does not support this OS
+                dlg = wx.MessageDialog(self.frame_modal, f"OpenCore Legacy patcher currently does not support macOS {os_data.os_conversion.convert_kernel_to_marketing_name(os_data.os_conversion.os_to_kernel(app_major))}. We highly recommend you select and older installer.\n\nThe newest version we officially support is macOS {os_data.os_conversion.convert_kernel_to_marketing_name(os_data.os_conversion.os_to_kernel(str(self.constants.os_support)))}", "Unsupported OS", wx.YES_NO | wx.ICON_WARNING)
+                if dlg.ShowModal() == wx.ID_NO:
+                    return
+        except ValueError:
+            pass
+
         self.frame.DestroyChildren()
         installer_name = f"macOS {app_dict['Version']} ({app_dict['Build']})"