Fix SDK version requirement

This has been tested to work against Unity 2019 so make 3.4.2 the minimum

Author: BlueAmulet

Packages/blueamulet.udonsharpoptimizer/package.json

@@ -5,11 +5,11 @@
   "description": "UdonSharp postprocessor to reduce instruction and variable counts",
   "gitDependencies": {},
   "vpmDependencies": {
-    "com.vrchat.worlds": "3.7.0"
+    "com.vrchat.worlds": "^3.4.2"
   },
   "author": {
     "name": "BlueAmulet"
   },
   "legacyFolders": {},
   "legacyFiles": {}
-}
+}