shaders: fixup no-std of graster-nodes

Author: Firestar99

node-graph/graster-nodes/Cargo.toml

@@ -25,7 +25,8 @@ std = [
 	"dep:serde",
 	"dep:specta",
 	"dep:glam",
-	"dep:graphene-raster-nodes-shaders"
+	"dep:graphene-raster-nodes-shaders",
+	"dep:kurbo"
 ]
 
 [dependencies]
@@ -53,7 +54,7 @@ rand = { workspace = true, optional = true }
 rand_chacha = { workspace = true, optional = true }
 fastnoise-lite = { workspace = true, optional = true }
 serde = { workspace = true, optional = true }
-kurbo = { workspace = true }
+kurbo = { workspace = true, optional = true }
 
 [dev-dependencies]
 tokio = { workspace = true }