Update ethabi requirement from 9.0.0 to 11.0.0

Updates the requirements on [ethabi](https://github.com/paritytech/ethabi) to permit the latest version.
- [Release notes](https://github.com/paritytech/ethabi/releases)
- [Changelog](https://github.com/paritytech/ethabi/blob/master/CHANGELOG.md)
- [Commits](paritytech/ethabi@v9.0.0...v11.0.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Cargo.toml

@@ -13,7 +13,7 @@ edition = "2018"
 
 [dependencies]
 arrayvec = "0.5.0"
-ethabi = "9.0.0"
+ethabi = "11.0.0"
 ethereum-types = "0.8.0"
 futures = "0.1.26"
 jsonrpc-core = "14.0.0"