Update realm to latest version

Contains minor changes to async usage in line with upstream API changes.

I believe a feedback issue we were seeing with offset changes (the only
component using async write flow) may have been resolved by these
upstream changes (see [release
notes](https://github.com/realm/realm-dotnet/releases/tag/10.14.0)) but
am not investigating further just yet.

osu.Game/Database/RealmAccess.cs

@@ -392,7 +392,7 @@ namespace osu.Game.Database
         {
             total_writes_async.Value++;
             using (var realm = getRealmInstance())
-                await realm.WriteAsync(action);
+                await realm.WriteAsync(() => action(realm));
         }
 
         /// <summary>