fix: no reason to limit Unity version

Runtime/IsExternalInit.cs

@@ -1,14 +1,8 @@
-#if false == UNITY_2022_1_OR_NEWER
-
 // NOTE: to use record & init accessor in Unity 2021
 //       https://stackoverflow.com/questions/62648189/testing-c-sharp-9-0-in-vs2019-cs0518-isexternalinit-is-not-defined-or-imported
 
 namespace System.Runtime.CompilerServices
 {
     [ComponentModel.EditorBrowsable(ComponentModel.EditorBrowsableState.Never)]
-    /*internal*/ class IsExternalInit
-    {
-    }
+    class IsExternalInit { }
 }
-
-#endif

package.json

@@ -1,7 +1,7 @@
 {
   "name": "com.sator-imaging.alt-source-generator",
   "displayName": "Alternative Source Generator for Unity",
-  "version": "3.0.0",
+  "version": "3.0.1",
   "unity": "2021.3",
   "description": "Ease-of-Use Source Generator Alternative for Unity.",
   "author": {