Dex: Don't deepClone Pokedex during load (#10611)

The only issue came from gen1 not using modData. After fixing that, everything just works.
You can test this by deepFreezing dataCache right after running Scripts.init and
then loading all the species for all the mods and running the test suite.

data/mods/gen1/scripts.ts

@@ -17,8 +17,9 @@ export const Scripts: ModdedBattleScriptsData = {
 	gen: 1,
 	init() {
 		for (const i in this.data.Pokedex) {
-			(this.data.Pokedex[i] as any).gender = 'N';
-			(this.data.Pokedex[i] as any).eggGroups = null;
+			const poke = this.modData('Pokedex', i);
+			poke.gender = 'N';
+			poke.eggGroups = null;
 		}
 	},
 	// BattlePokemon scripts.

sim/dex.ts

@@ -524,13 +524,7 @@ export class ModdedDex {
 						delete childTypedData[entryId];
 					} else if (!(entryId in childTypedData)) {
 						// If it doesn't exist it's inherited from the parent data
-						if (dataType === 'Pokedex') {
-							// Pokedex entries can be modified too many different ways
-							// e.g. inheriting different formats-data/learnsets
-							childTypedData[entryId] = this.deepClone(parentTypedData[entryId]);
-						} else {
-							childTypedData[entryId] = parentTypedData[entryId];
-						}
+						childTypedData[entryId] = parentTypedData[entryId];
 					} else if (childTypedData[entryId] && childTypedData[entryId].inherit) {
 						// {inherit: true} can be used to modify only parts of the parent data,
 						// instead of overwriting entirely