Remove itertools since it is unused

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "av1-grain"
-version = "0.2.2"
+version = "0.2.3"
 edition = "2021"
 rust-version = "1.59.0"
 license = "BSD-2-Clause"
@@ -13,7 +13,6 @@ documentation = "https://docs.rs/av1-grain"
 [dependencies]
 anyhow = "1.0.58"
 arrayvec = "0.7.2"
-itertools = { version = "0.12", optional = true }
 log = "0.4.17"
 nom = { version = "7.1.1", optional = true }
 num-rational = { version = "0.4.1", optional = true }
@@ -30,7 +29,7 @@ unstable = []
 create = []
 diff = ["num-rational", "v_frame"]
 estimate = ["v_frame"]
-parse = ["itertools", "nom"]
+parse = ["nom"]
 serialize = ["serde", "arrayvec/serde"]
 
 [profile.release]