Removed `RESTART` built-in from `start` particle shader function

servers/rendering/shader_types.cpp

@@ -342,7 +342,6 @@ ShaderTypes::ShaderTypes() {
 	shader_modes[RS::SHADER_PARTICLES].functions["start"].built_ins["VELOCITY"] = ShaderLanguage::TYPE_VEC3;
 	shader_modes[RS::SHADER_PARTICLES].functions["start"].built_ins["MASS"] = ShaderLanguage::TYPE_FLOAT;
 	shader_modes[RS::SHADER_PARTICLES].functions["start"].built_ins["ACTIVE"] = ShaderLanguage::TYPE_BOOL;
-	shader_modes[RS::SHADER_PARTICLES].functions["start"].built_ins["RESTART"] = constt(ShaderLanguage::TYPE_BOOL);
 	shader_modes[RS::SHADER_PARTICLES].functions["start"].built_ins["CUSTOM"] = ShaderLanguage::TYPE_VEC4;
 	shader_modes[RS::SHADER_PARTICLES].functions["start"].built_ins["TRANSFORM"] = ShaderLanguage::TYPE_MAT4;
 	shader_modes[RS::SHADER_PARTICLES].functions["start"].built_ins["LIFETIME"] = constt(ShaderLanguage::TYPE_FLOAT);