Ignore extra_unused_type_parameters clippy lint in test

    error: type parameter goes unused in function definition
       --> test_suite/tests/test_gen.rs:756:10
        |
    756 | fn assert<T: Serialize + DeserializeOwned>() {}
        |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        |
        = help: consider removing the parameter
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#extra_unused_type_parameters
        = note: `-D clippy::extra-unused-type-parameters` implied by `-D clippy::all`

    error: type parameter goes unused in function definition
       --> test_suite/tests/test_gen.rs:757:14
        |
    757 | fn assert_ser<T: Serialize>() {}
        |              ^^^^^^^^^^^^^^
        |
        = help: consider removing the parameter
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#extra_unused_type_parameters

    error: type parameter goes unused in function definition
      --> test_suite/tests/test_serde_path.rs:20:18
       |
    20 |     pub fn assert<T>()
       |                  ^^^
       |
       = help: consider removing the parameter
       = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#extra_unused_type_parameters
       = note: `-D clippy::extra-unused-type-parameters` implied by `-D clippy::all`

test_suite/tests/test_gen.rs

@@ -7,6 +7,7 @@
     unknown_lints,
     mixed_script_confusables,
     clippy::derive_partial_eq_without_eq,
+    clippy::extra_unused_type_parameters,
     clippy::items_after_statements,
     clippy::missing_errors_doc,
     clippy::missing_panics_doc,

test_suite/tests/test_serde_path.rs

@@ -1,4 +1,7 @@
-#![allow(clippy::type_repetition_in_bounds)]
+#![allow(
+    clippy::extra_unused_type_parameters,
+    clippy::type_repetition_in_bounds
+)]
 
 #[test]
 fn test_gen_custom_serde() {