macros: use call_site hygiene to avoid unused qualification (#7866)

tests-build/tests/pass/use_builder_outer.rs

@@ -0,0 +1,9 @@
+#![deny(unused_qualifications)]
+
+use tests_build::tokio;
+pub use tokio::runtime;
+
+#[tokio::main]
+async fn main() {
+    if true {}
+}