refactor(frontend): menuのdividerをnullで表現するのをやめる

packages/frontend/src/components/MkNote.vue

@@ -464,7 +464,7 @@ function showRenoteMenu(viaKeyboard = false): void {
 		pleaseLogin();
 		os.popupMenu([
 			getCopyNoteLinkMenu(note.value, i18n.ts.copyLinkRenote),
-			null,
+			{ type: 'divider' },
 			getUnrenote(),
 		], renoteTime.value, {
 			viaKeyboard: viaKeyboard,
@@ -472,7 +472,7 @@ function showRenoteMenu(viaKeyboard = false): void {
 	} else {
 		os.popupMenu([
 			getCopyNoteLinkMenu(note.value, i18n.ts.copyLinkRenote),
-			null,
+			{ type: 'divider' },
 			getAbuseNoteMenu(note.value, i18n.ts.reportAbuseRenote),
 			$i.isModerator || $i.isAdmin ? getUnrenote() : undefined,
 		], renoteTime.value, {