Remove arbitrary-fuzz (#8936)

We have duplicated features which enable `arbitrary` throughout the codebase. These are `arbitrary` and `arbitrary-fuzz`. I think historically these were supposed to be distinct however in practice these function identically and so we can unify them into a single feature to avoid confusion.


Co-Authored-By: Mac L <mjladson@pm.me>

consensus/state_processing/src/envelope_processing.rs

@@ -21,7 +21,7 @@ macro_rules! envelope_verify {
 }
 
 /// The strategy to be used when validating the payloads state root.
-#[cfg_attr(feature = "arbitrary-fuzz", derive(arbitrary::Arbitrary))]
+#[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
 #[derive(PartialEq, Clone, Copy)]
 pub enum VerifyStateRoot {
     /// Validate state root.