Revert "chore: disable warnings in old CI (#4691)"

This reverts commit b24df49a9d so we can
merge the CHANGELOG changes in #4691 into master.

tests-build/tests/macros_clippy.rs

@@ -0,0 +1,7 @@
+#[cfg(feature = "full")]
+#[tokio::test]
+async fn test_with_semicolon_without_return_type() {
+    #![deny(clippy::semicolon_if_nothing_returned)]
+
+    dbg!(0);
+}