fix: wrong texture name in Texture Transform check

UnityGLTF/Assets/UnityGLTF/Editor/Scripts/ShaderGraph/InternalShaderGraph/ShaderGraphHelpers.cs

@@ -116,7 +116,7 @@ public static void ValidateMaterialKeywords(Material material)
 
 			if (!material.IsKeywordEnabled("_TEXTURE_TRANSFORM_ON"))
 			{
-				if (material.mainTextureScale != Vector2.one || material.mainTextureOffset != Vector2.zero)
+				if (material.GetTextureScale("baseColorTexture") != Vector2.one || material.GetTextureOffset("baseColorTexture") != Vector2.zero)
 				{
 					material.SetKeyword("_TEXTURE_TRANSFORM", true);
 				}