[unity] Corrected spine-csharp package.json file, it contained `src` as folders directory (where it already resides).

spine-csharp/src/package.json

@@ -11,9 +11,6 @@
 	},
 	"dependencies": {
 	},
-	"files": [
-		"src"
-	],
 	"repository": {
 		"type": "git",
 		"url": "[email protected]:EsotericSoftware/spine-runtimes.git"