Sanitize JSON schema

Trying to fix #70 blindly
Ref:
- https://ai.google.dev/api/caching#Schema
- https://json-schema.org/understanding-json-schema/keywords#dollarschema

Author: johnd0e

src/worker.mjs

@@ -241,6 +241,7 @@ const adjustProps = (schemaPart) => {
 const adjustSchema = (schema) => {
   const obj = schema[schema.type];
   delete obj.strict;
+  delete obj.parameters?.$schema;
   return adjustProps(schema);
 };