Fix persisting sleep animation when sprite is already loaded

Ensure that a Pokémon's animation speed is reset properly after saving
and quitting. Previously, if a Pokémon was put to sleep, which slows
its framerate, saving and quitting would result in the slower framerate
persisting even though the Pokémon was no longer asleep. This fix adds
an else condition to reset the frameRate to 12 if the sprite is already
loaded upon resuming the game.

Fixes #4465

src/data/pokemon-species.ts

@@ -484,6 +484,8 @@ export abstract class PokemonSpeciesForm {
             frameRate: 12,
             repeat: -1
           });
+        } else {
+          scene.anims.get(spriteKey).frameRate = 12;
         }
         let spritePath = this.getSpriteAtlasPath(female, formIndex, shiny, variant).replace("variant/", "").replace(/_[1-3]$/, "");
         const useExpSprite = scene.experimentalSprites && scene.hasExpSprite(spriteKey);