Remove all calls to `Realm.Refresh` to fix blocking overhead from subscriptions

Turns out this is not required if realm is aware of a
`SynchronizationContext`. See
https://github.com/realm/realm-dotnet/discussions/2775#discussioncomment-2005412
for further reading.

osu.Game/Database/EFToRealmMigrator.cs

@@ -46,9 +46,6 @@ public void Run()
                 migrateScores(ef);
             }
 
-            Logger.Log("Refreshing realm...", LoggingTarget.Database);
-            realmContextFactory.Refresh();
-
             // Delete the database permanently.
             // Will cause future startups to not attempt migration.
             Logger.Log("Migration successful, deleting EF database", LoggingTarget.Database);

osu.Game/Database/RealmContextFactory.cs

@@ -61,10 +61,10 @@ public class RealmContextFactory : IDisposable, IRealmFactory
 
         private readonly ThreadLocal<bool> currentThreadCanCreateContexts = new ThreadLocal<bool>();
 
-        private static readonly GlobalStatistic<int> refreshes = GlobalStatistics.Get<int>(@"Realm", @"Dirty Refreshes");
         private static readonly GlobalStatistic<int> contexts_created = GlobalStatistics.Get<int>(@"Realm", @"Contexts (Created)");
 
         private readonly object contextLock = new object();
+
         private Realm? context;
 
         public Realm Context
@@ -169,18 +169,6 @@ private void cleanupPendingDeletions()
         /// <returns></returns>
         public bool Compact() => Realm.Compact(getConfiguration());
 
-        /// <summary>
-        /// Perform a blocking refresh on the main realm context.
-        /// </summary>
-        public void Refresh()
-        {
-            lock (contextLock)
-            {
-                if (context?.Refresh() == true)
-                    refreshes.Value++;
-            }
-        }
-
         public Realm CreateContext()
         {
             if (isDisposed)

osu.Game/OsuGameBase.cs

@@ -351,13 +351,6 @@ protected override void LoadComplete()
             FrameStatistics.ValueChanged += e => fpsDisplayVisible.Value = e.NewValue != FrameStatisticsMode.None;
         }
 
-        protected override void Update()
-        {
-            base.Update();
-
-            realmFactory.Refresh();
-        }
-
         protected override IReadOnlyDependencyContainer CreateChildDependencies(IReadOnlyDependencyContainer parent) =>
             dependencies = new DependencyContainer(base.CreateChildDependencies(parent));