rust: remove unused Ethereum wrappers for C

Author: benma

src/rust/bitbox02-rust-c/src/app_ethereum.rs

@@ -40,9 +40,6 @@ mod sha2;
 #[cfg(feature = "firmware")]
 mod workflow;
 
-#[cfg(feature = "app-ethereum")]
-pub mod app_ethereum;
-
 // Whenever execution reaches somewhere it isn't supposed to rust code will "panic". Our panic
 // handler will print the available information on the screen. If we compile with `panic=abort`
 // this code will never get executed.