sc-cli: Remove SubstrateCli::native_runtime_version function (#14511)

The native runtime will be removed in the near future and thus this function will not be required
anymore.

\# Code changes

Downstream users just need to remove `native_runtime_version` from their implementation of the
`SubstrateCli` trait.

substrate/bin/node-template/node/src/command.rs

@@ -6,7 +6,7 @@ use crate::{
 };
 use frame_benchmarking_cli::{BenchmarkCmd, ExtrinsicFactory, SUBSTRATE_REFERENCE_HARDWARE};
 use node_template_runtime::{Block, EXISTENTIAL_DEPOSIT};
-use sc_cli::{ChainSpec, RuntimeVersion, SubstrateCli};
+use sc_cli::SubstrateCli;
 use sc_service::PartialComponents;
 use sp_keyring::Sr25519Keyring;
 
@@ -46,10 +46,6 @@ impl SubstrateCli for Cli {
 				Box::new(chain_spec::ChainSpec::from_json_file(std::path::PathBuf::from(path))?),
 		})
 	}
-
-	fn native_runtime_version(_: &Box<dyn ChainSpec>) -> &'static RuntimeVersion {
-		&node_template_runtime::VERSION
-	}
 }
 
 /// Parse and run command line arguments