remove redundant import (#2795)

Co-authored-by: Emilio Cobos Álvarez <emilio@crisal.io>

Author: tshepang

bindgen/ir/analysis/mod.rs

@@ -216,7 +216,7 @@ where
 #[cfg(test)]
 mod tests {
     use super::*;
-    use crate::{HashMap, HashSet};
+    use crate::HashSet;
 
     // Here we find the set of nodes that are reachable from any given
     // node. This is a lattice mapping nodes to subsets of all nodes. Our join