Remove purple chest despawn code

The blind despawn fix makes this unnecessary. Dungeon Entrance event
hook retained for possible future use, but is commented out.

events.asm

@@ -13,18 +13,10 @@ OnDrawHud:
 	JSL.l DrawDungeonCompassCounts
 RTL
 ;--------------------------------------------------------------------------------
-OnDungeonEntrance:
-	PHA : PHP
-		SEP #$20 ; set 8-bit accumulator
-		LDA $040C : CMP #$FF : BEQ + ; don't do this unless it's a real dungeon
-		REP #$20 : LDA $A0 : CMP.w #18 : BEQ + : SEP #$20 ; skip if we're in the sanctuary
-		LDA $7EF3CC ; load follower
-		CMP #$0C : BNE + ; skip if not the purple chest
-			LDA #$00 : STA $7EF3CC
-		+ ; this might get hit from above in either accumulator mode
-	PLP : PLA
-	STA $7EC172 ; thing we wrote over
-RTL
+;OnDungeonEntrance:
+;
+;	STA $7EC172 ; thing we wrote over
+;RTL
 ;--------------------------------------------------------------------------------
 OnDungeonExit:
 	STA $040C : STZ $04AC ; thing we wrote over