Revert back to std::error::Error

Fixes compile error on Rust 1.75.0 since
`core::error` is only available after 1.81.0.

Author: ValuedMammal

src/client.rs

@@ -43,7 +43,7 @@ impl Client {
     ) -> Result<T, Error>
     where
         T: for<'de> Deserialize<'de>,
-        E: core::error::Error + Send + Sync + 'static,
+        E: std::error::Error + Send + Sync + 'static,
     {
         let method = rpc.method();
         let raw_value = if params.is_empty() {
@@ -69,7 +69,7 @@ impl Client {
     ) -> Result<T, Error>
     where
         T: for<'de> Deserialize<'de>,
-        E: core::error::Error + Send + Sync + 'static,
+        E: std::error::Error + Send + Sync + 'static,
     {
         let method = rpc.method();
         let raw_value = if params.is_empty() {

src/error.rs

@@ -21,7 +21,7 @@ pub enum Error {
     /// JSON-RPC error from the server.
     JsonRpc(jsonrpc::Error),
     /// model types error
-    Model(Box<dyn core::error::Error + Send + Sync>),
+    Model(Box<dyn std::error::Error + Send + Sync>),
     /// nonce mismatch
     NonceMismatch,
     /// integer conversion
@@ -43,22 +43,22 @@ impl fmt::Display for Error {
     }
 }
 
-impl core::error::Error for Error {}
+impl std::error::Error for Error {}
 
 impl Error {
     /// Convert `e` to a [`Error::Model`] error.
     #[cfg(feature = "bitreq")]
     pub(crate) fn model<E>(e: E) -> Self
     where
-        E: core::error::Error + Send + Sync + 'static,
+        E: std::error::Error + Send + Sync + 'static,
     {
         Self::Model(Box::new(e))
     }
 
     /// Convert `e` to a [`jsonrpc::Error::Transport`] error.
     pub(crate) fn transport<E>(e: E) -> Self
     where
-        E: core::error::Error + Send + Sync + 'static,
+        E: std::error::Error + Send + Sync + 'static,
     {
         Self::JsonRpc(jsonrpc::Error::Transport(Box::new(e)))
     }