Remove unused pin from null driver

src/drivers/null.rs

@@ -1,13 +1,11 @@
 use crate::drivers::RelayDriver;
 use crate::errors::EmgauwaControllerError;
 
-pub struct NullDriver {
-	pub pin: u8,
-}
+pub struct NullDriver {}
 
 impl NullDriver {
-	pub fn new(pin: u8) -> Self {
-		Self { pin }
+	pub fn new() -> Self {
+		Self {}
 	}
 }