[unity] Fixed URP unlit shader incorrect shader stripping. Removed unnecessary problematic multi_compile variants. Closes #2162.

spine-unity/Modules/com.esotericsoftware.spine.urp-shaders/Shaders/Spine-Skeleton-URP.shader

@@ -35,13 +35,6 @@ Shader "Universal Render Pipeline/Spine/Skeleton" {
 			#pragma prefer_hlslcc gles
 			#pragma exclude_renderers d3d11_9x
 
-			// -------------------------------------
-			// Universal Pipeline keywords
-			#pragma multi_compile _ _MAIN_LIGHT_SHADOWS
-			#pragma multi_compile _ _MAIN_LIGHT_SHADOWS_CASCADE
-			#pragma multi_compile _ _ADDITIONAL_LIGHT_SHADOWS
-			#pragma multi_compile _ _SHADOWS_SOFT
-
 			// -------------------------------------
 			// Unity defined keywords
 			#pragma multi_compile_fog

spine-unity/Modules/com.esotericsoftware.spine.urp-shaders/package.json

@@ -2,7 +2,7 @@
   "name": "com.esotericsoftware.spine.urp-shaders",
   "displayName": "Spine Universal RP Shaders",
   "description": "This plugin provides universal render pipeline (URP) shaders for the spine-unity runtime.\n\nPrerequisites:\nIt requires a working installation of the spine-unity runtime, version 4.1.\n(See http://esotericsoftware.com/git/spine-runtimes/spine-unity)",
-  "version": "4.1.4",
+  "version": "4.1.5",
   "unity": "2019.3",
   "author": {
     "name": "Esoteric Software",