fix cloned string cleanup

dynamodb/expression.odin

@@ -480,7 +480,7 @@ parse_key_condition_expression_string :: proc(request_body: []byte) -> (expr: st
 		return
 	}
 
-	expr = string(kce_str)
+	expr = strings.clone(string(kce_str))
 	ok = true
 	return
 }
@@ -488,6 +488,7 @@ parse_key_condition_expression_string :: proc(request_body: []byte) -> (expr: st
 // Convenience: parse a complete Query key condition from request body
 parse_query_key_condition :: proc(request_body: []byte) -> (kc: Key_Condition, ok: bool) {
 	expression := parse_key_condition_expression_string(request_body) or_return
+	defer delete(expression)
 
 	attr_names := parse_expression_attribute_names(request_body)
 	defer {