Apply QTBUG-58610 fix only on Windows

Author: markotoplak

orangecanvas/application/application.py

@@ -151,7 +151,7 @@ def __init__(self, argv):
                 sh.setShowShortcutsInContextMenus(True)
         if QT_VERSION_INFO < (5, 15):  # QTBUG-61707
             macos_set_nswindow_tabbing(False)
-        if QT_VERSION_INFO < (6, 0):  # QTBUG-58610
+        if QT_VERSION_INFO < (6, 0) and sys.platform == "win32":  # QTBUG-58610
             # https://github.com/musescore/MuseScore/pull/5820
             QApplication.setFont(QApplication.font("QMessageBox"))
         self.configureStyle()