Remove TerrainShader.js

continuation of #18098

utils/modularize.js

@@ -216,7 +216,6 @@ var files = [
 	{ path: 'shaders/SobelOperatorShader.js', dependencies: [], ignoreList: [] },
 	{ path: 'shaders/SSAOShader.js', dependencies: [], ignoreList: [] },
 	{ path: 'shaders/TechnicolorShader.js', dependencies: [], ignoreList: [] },
-	{ path: 'shaders/TerrainShader.js', dependencies: [], ignoreList: [] },
 	{ path: 'shaders/ToneMapShader.js', dependencies: [], ignoreList: [] },
 	{ path: 'shaders/ToonShader.js', dependencies: [], ignoreList: [] },
 	{ path: 'shaders/TranslucentShader.js', dependencies: [], ignoreList: [] },