Handle cancellation at more points during Player initialisation

As discussed in discord, this will help avoid null references during
cancellation which can otherwise be quite confusing to debug.

osu.Game/Screens/Play/Player.cs

@@ -249,6 +249,9 @@ private void load(AudioManager audio, OsuConfigManager config, OsuGameBase game,
             // this is intentionally done in two stages to ensure things are in a loaded state before exposing the ruleset to skin sources.
             GameplayClockContainer.Add(rulesetSkinProvider);
 
+            if (cancellationToken.IsCancellationRequested)
+                return;
+
             rulesetSkinProvider.AddRange(new Drawable[]
             {
                 failAnimationLayer = new FailAnimation(DrawableRuleset)
@@ -279,6 +282,9 @@ private void load(AudioManager audio, OsuConfigManager config, OsuGameBase game,
                 },
             });
 
+            if (cancellationToken.IsCancellationRequested)
+                return;
+
             if (Configuration.AllowRestart)
             {
                 rulesetSkinProvider.Add(new HotkeyRetryOverlay