Runtime APIs; don't ask for validation hash anywhere except new_static (#947)

* remove validation hash where not wanted

* .into()

* fix example

* cargo fmt

examples/examples/runtime_calls.rs

@@ -68,11 +68,8 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
     println!("AccountNonceApi_account_nonce for Alice: {:?}", nonce);
 
     // Dynamic calls.
-    let runtime_api_call = subxt::dynamic::runtime_api_call(
-        "Metadata_metadata_versions",
-        Vec::<Value<()>>::new(),
-        None,
-    );
+    let runtime_api_call =
+        subxt::dynamic::runtime_api_call("Metadata_metadata_versions", Vec::<Value<()>>::new());
     let versions = api
         .runtime_api()
         .at_latest()

subxt/src/runtime_api/runtime_payload.rs

@@ -97,15 +97,11 @@ pub type DynamicRuntimeApiPayload = Payload<Composite<()>, DecodedValueThunk>;
 
 impl<ReturnTy, ArgsData> Payload<ArgsData, ReturnTy> {
     /// Create a new [`Payload`].
-    pub fn new(
-        fn_name: impl Into<String>,
-        args_data: ArgsData,
-        validation_hash: Option<[u8; 32]>,
-    ) -> Self {
+    pub fn new(fn_name: impl Into<String>, args_data: ArgsData) -> Self {
         Payload {
             fn_name: Cow::Owned(fn_name.into()),
             args_data,
-            validation_hash,
+            validation_hash: None,
             _marker: PhantomData,
         }
     }
@@ -151,12 +147,6 @@ impl<ReturnTy, ArgsData> Payload<ArgsData, ReturnTy> {
 pub fn dynamic(
     fn_name: impl Into<String>,
     args_data: impl Into<Composite<()>>,
-    hash: Option<[u8; 32]>,
 ) -> DynamicRuntimeApiPayload {
-    DynamicRuntimeApiPayload {
-        fn_name: Cow::Owned(fn_name.into()),
-        args_data: args_data.into(),
-        validation_hash: hash,
-        _marker: std::marker::PhantomData,
-    }
+    Payload::new(fn_name, args_data.into())
 }