Add back party heal to endless mode

src/battle-phases.ts

@@ -461,10 +461,7 @@ export class SelectBiomePhase extends BattlePhase {
     const currentBiome = this.scene.arena.biomeType;
 
     const setNextBiome = (nextBiome: Biome) => {
-      if (this.scene.gameMode === GameMode.CLASSIC)
-        this.scene.unshiftPhase(new PartyHealPhase(this.scene, false));
-      else
-        this.scene.fadeOutBgm(2000, true);
+      this.scene.unshiftPhase(new PartyHealPhase(this.scene, false));
       this.scene.unshiftPhase(new SwitchBiomePhase(this.scene, nextBiome));
       this.end();
     };