pubsub: v1.21.0

1.21.0 (2022-04-26)

Features

• pubsub: deprecate synchronous mode (#5910) (bda5179)

Bug Fixes

• pubsub: enable updating enable_exactly_once_delivery in fake pubsub (#5940) (ee44bf6)
• pubsub: nack messages properly with error from receive scheduler (#5909) (80edea4)