chore: checkpoint before Python removal

vendor/json-patch/tests/schemars.rs

@@ -0,0 +1,9 @@
+#[cfg(feature = "schemars")]
+#[test]
+fn schema() {
+    use json_patch::*;
+
+    let schema = schemars::schema_for!(PatchOperation);
+    let json = serde_json::to_string_pretty(&schema).unwrap();
+    expectorate::assert_contents("tests/schemars.json", &json);
+}