Deck options: hide webview after showing dialog

This seems to reduce flicker, presumably because the webview doesn't pick
up the correct geometry until the dialog is shown.

qt/aqt/deckoptions.py

@@ -33,7 +33,6 @@ class DeckOptionsDialog(QDialog):
         self.mw = mw
         self._deck = deck
         self._setup_ui()
-        self.show()
 
     def _setup_ui(self) -> None:
         self.setWindowModality(Qt.WindowModality.ApplicationModal)
@@ -44,12 +43,13 @@ class DeckOptionsDialog(QDialog):
         addCloseShortcut(self)
 
         self.web = AnkiWebView(title=self.TITLE)
-        self.web.setVisible(False)
         self.web.load_ts_page("deck-options")
         layout = QVBoxLayout()
         layout.setContentsMargins(0, 0, 0, 0)
         layout.addWidget(self.web)
         self.setLayout(layout)
+        self.show()
+        self.web.hide_while_preserving_layout()
 
         self.web.eval(
             f"""const $deckOptions = anki.setupDeckOptions({self._deck["id"]});"""