remove redundant imports

detects redundant imports that can be eliminated.

for #117772 :

In order to facilitate review and modification, split the checking code and
removing redundant imports code into two PR.

compiler/rustc_mir_transform/src/const_goto.rs

@@ -17,7 +17,6 @@
 //! }
 //! ```
 
-use crate::MirPass;
 use rustc_middle::mir::*;
 use rustc_middle::ty::TyCtxt;
 use rustc_middle::{mir::visit::Visitor, ty::ParamEnv};