chore: checkpoint before Python removal

vendor/tracing-subscriber/tests/fmt_max_level_hint.rs

@@ -0,0 +1,10 @@
+#![cfg(feature = "fmt")]
+use tracing_subscriber::filter::LevelFilter;
+
+#[test]
+fn fmt_sets_max_level_hint() {
+    tracing_subscriber::fmt()
+        .with_max_level(LevelFilter::DEBUG)
+        .init();
+    assert_eq!(LevelFilter::current(), LevelFilter::DEBUG);
+}