chore: checkpoint before Python removal

vendor/tracing-attributes/tests/ui.rs

@@ -0,0 +1,15 @@
+// Only test on stable, since UI tests are bound to change over time
+
+#[rustversion::stable]
+#[test]
+fn pass() {
+    let t = trybuild::TestCases::new();
+    t.pass("tests/ui/pass/*.rs");
+}
+
+#[rustversion::stable]
+#[test]
+fn compile_fail() {
+    let t = trybuild::TestCases::new();
+    t.compile_fail("tests/ui/fail/*.rs");
+}