Revert to previous bound in drum roll tick generation

While `EndTime + tickSpacing` _was_ closer to what stable was using, it
could cause undesirable edge cases wherein a tick would be spawned
outside of the drum roll's duration
(see https://github.com/ppy/osu/pull/23768/files#r1222073027).

For this reason, stick with the old code for now, as it is not as
susceptible to that sort of breakage.

osu.Game.Rulesets.Taiko/Objects/DrumRoll.cs

@@ -86,7 +86,7 @@ namespace osu.Game.Rulesets.Taiko.Objects
 
             bool first = true;
 
-            for (double t = StartTime; t < EndTime + tickSpacing; t += tickSpacing)
+            for (double t = StartTime; t < EndTime + tickSpacing / 2; t += tickSpacing)
             {
                 cancellationToken.ThrowIfCancellationRequested();