feat!: relax ProviderBuilder bounds (#2276)

Allows:
- calling the filler helper methods at any point of the builder
- using on_anvil* with any network

Author: DaniPopes

crates/contract/src/multicall.rs

@@ -126,11 +126,7 @@ mod tests {
 
         let err = multicall.aggregate3().await.unwrap_err();
 
-        assert!(
-            err.to_string().contains("execution reverted: Multicall3: call failed"),
-            "{:?}",
-            err
-        );
+        assert!(err.to_string().contains("Multicall3: call failed"), "{err}");
 
         let failing_call = CallItemBuilder::new(dummy.fail()).allow_failure(true);
         let multicall = provider

crates/node-bindings/src/nodes/anvil.rs

@@ -416,21 +416,13 @@ impl Anvil {
             }
 
             if !private_keys.is_empty() {
-                let (default, remaining) = private_keys.split_first().unwrap();
-                let pks = remaining
-                    .iter()
-                    .map(|key| {
-                        let mut signer = LocalSigner::from(key.clone());
-                        signer.set_chain_id(chain_id);
-                        signer
-                    })
-                    .collect::<Vec<_>>();
-
-                let mut default_signer = LocalSigner::from(default.clone());
-                default_signer.set_chain_id(chain_id);
-                let mut w = EthereumWallet::new(default_signer);
-
-                for pk in pks {
+                let mut private_keys = private_keys.iter().map(|key| {
+                    let mut signer = LocalSigner::from(key.clone());
+                    signer.set_chain_id(chain_id);
+                    signer
+                });
+                let mut w = EthereumWallet::new(private_keys.next().unwrap());
+                for pk in private_keys {
                     w.register_signer(pk);
                 }
                 wallet = Some(w);