Remove c-kzg (#8930)

#7330


  Removes `c-kzg` from our `kzg` crate and rely fully on the `rust_eth_kzg` crate.

This removes the old `Blob` type entirely and instead handles `rust_eth_kzg::KzgBlobRef`s directly which allows us to avoid some extra stack allocations . Similarly, we make `Bytes32` and `Bytes48` type aliases rather than structs as this fits better with the new `rust_eth_kzg` API.


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

crypto/kzg/src/kzg_proof.rs

@@ -1,4 +1,4 @@
-use c_kzg::BYTES_PER_PROOF;
+use crate::BYTES_PER_PROOF;
 use serde::de::{Deserialize, Deserializer};
 use serde::ser::{Serialize, Serializer};
 use ssz_derive::{Decode, Encode};
@@ -11,12 +11,6 @@ use tree_hash::{PackedEncoding, TreeHash};
 #[ssz(struct_behaviour = "transparent")]
 pub struct KzgProof(pub [u8; BYTES_PER_PROOF]);
 
-impl From<KzgProof> for c_kzg::Bytes48 {
-    fn from(value: KzgProof) -> Self {
-        value.0.into()
-    }
-}
-
 impl KzgProof {
     /// Creates a valid proof using `G1_POINT_AT_INFINITY`.
     pub fn empty() -> Self {