fix couple of clippy findings:

filter_map_identity
iter_kv_map
needless_question_mark
redundant_at_rest_pattern
filter_next
derivable_impls

Author: matthiaskrgr

test/src/lib.rs

@@ -183,8 +183,7 @@ pub fn test_main_static_abort(tests: &[&TestDescAndFn]) {
 
         let test = tests
             .into_iter()
-            .filter(|test| test.desc.name.as_slice() == name)
-            .next()
+            .find(|test| test.desc.name.as_slice() == name)
             .unwrap_or_else(|| panic!("couldn't find a test with the provided name '{name}'"));
         let TestDescAndFn { desc, testfn } = test;
         match testfn.into_runnable() {