chainable.rbs in httpx-1.2.0

- old
+ new

@@ -32,9 +32,10 @@
               | (:aws_sigv4, ?options) -> Plugins::awsSigV4Session
               | (:grpc, ?options) -> Plugins::grpcSession
               | (:response_cache, ?options) -> Plugins::sessionResponseCache
               | (:circuit_breaker, ?options) -> Plugins::sessionCircuitBreaker
               | (:oauth, ?options) -> Plugins::sessionOAuth
+              | (:callbacks, ?options) -> Plugins::sessionCallbacks
               | (Symbol | Module, ?options) { (Class) -> void } -> Session
               | (Symbol | Module, ?options) -> Session
 
     private
 