Remove requirement of using Python 3.10 and below

- I added a 'legacy mode' flag to revert https://github.com/HearthSim/UnityPack/pull/101 as it caused problems on Rei
 - I tested the new setup (using custom unitypack) vs old one, and the output .asset files were bit-for-bit identical

scripts/UnityTextModifier.py

@@ -133,7 +133,7 @@ with open(sys.argv[1], "rb") as assetsFile:
 	edits = newEdits
 
 	assetsFile.seek(0)
-	assets = Asset.from_file(assetsFile)
+	assets = Asset.from_file(assetsFile, legacy_mode=True)
 	for id, obj in assets.objects.items():
 		for edit in edits:
 			edit.checkObject(id, obj, bundle)