feat: update SafeErc20 to newer Solidity version

contracts/src/lib.rs

@@ -83,9 +83,9 @@ impl IErc20 for MyContract {
 */
 
 #![allow(
-    clippy::module_name_repetitions,
-    clippy::used_underscore_items,
-    deprecated
+  clippy::module_name_repetitions,
+  clippy::used_underscore_items,
+  deprecated
 )]
 #![cfg_attr(not(any(test, feature = "export-abi")), no_std, no_main)]
 #![cfg_attr(coverage_nightly, feature(coverage_attribute))]
@@ -95,4 +95,4 @@ extern crate alloc;
 pub mod access;
 pub mod finance;
 pub mod token;
-pub mod utils;
+pub mod utils;

contracts/src/token/erc20/mod.rs

@@ -66,7 +66,7 @@ mod sol {
         #[derive(Debug)]
         #[allow(missing_docs)]
         error ERC20InvalidReceiver(address receiver);
-        /// Indicates a failure with the `spender`’s `allowance`. Used in
+        /// Indicates a failure with the `spender`'s `allowance`. Used in
         /// transfers.
         ///
         /// * `spender` - Address that may be allowed to operate on tokens without
@@ -109,7 +109,7 @@ pub enum Error {
     InvalidSender(ERC20InvalidSender),
     /// Indicates a failure with the token `receiver`. Used in transfers.
     InvalidReceiver(ERC20InvalidReceiver),
-    /// Indicates a failure with the `spender`’s `allowance`. Used in
+    /// Indicates a failure with the `spender`'s `allowance`. Used in
     /// transfers.
     InsufficientAllowance(ERC20InsufficientAllowance),
     /// Indicates a failure with the `spender` to be approved. Used in
@@ -272,11 +272,6 @@ pub trait IErc20 {
     ) -> Result<bool, Self::Error>;
 }
 
-#[public]
-#[implements(IErc20<Error = Error>)]
-impl Erc20 {}
-
-#[public]
 impl IErc20 for Erc20 {
     type Error = Error;