remove deprecated shader function (#28901)

Co-authored-by: aardgoose <[email protected]>

src/renderers/shaders/ShaderChunk/colorspace_pars_fragment.glsl.js

@@ -32,13 +32,4 @@ vec4 sRGBTransferOETF( in vec4 value ) {
 	return vec4( mix( pow( value.rgb, vec3( 0.41666 ) ) * 1.055 - vec3( 0.055 ), value.rgb * 12.92, vec3( lessThanEqual( value.rgb, vec3( 0.0031308 ) ) ) ), value.a );
 }
 
-// @deprecated, r156
-vec4 LinearToLinear( in vec4 value ) {
-	return value;
-}
-
-// @deprecated, r156
-vec4 LinearTosRGB( in vec4 value ) {
-	return sRGBTransferOETF( value );
-}
 `;