Remove unused normal_flip chunk

src/renderers/shaders/ShaderLib/meshbasic_frag.glsl

@@ -54,7 +54,6 @@ void main() {
 
 	vec3 outgoingLight = reflectedLight.indirectDiffuse;
 
-	#include <normal_flip>
 	#include <envmap_fragment>
 
 	gl_FragColor = vec4( outgoingLight, diffuseColor.a );

src/renderers/shaders/ShaderLib/meshlambert_frag.glsl

@@ -71,7 +71,6 @@ void main() {
 
 	vec3 outgoingLight = reflectedLight.directDiffuse + reflectedLight.indirectDiffuse + totalEmissiveRadiance;
 
-	#include <normal_flip>
 	#include <envmap_fragment>
 
 	gl_FragColor = vec4( outgoingLight, diffuseColor.a );