[Bug] The pendingRequest resource may leak

[wolfstudy]

Expected behavior

When a request error occurs, expect the pendingRequest resource to be shut down normally

Actual behavior

When we clean up the cache resources of the producer or consumer on the client side, in fact we need to clean up the corresponding pendingRequest resources at the same time, otherwise it may cause resource leakage

Steps to reproduce

For more detailed information, refer to https://github.com/apache/pulsar-client-go/pull/622