dio 5.11.1

What's new

• Fix response stream not propagating backpressure to the underlying socket.
  When a consumer paused the stream, the source subscription was never paused,
  so the network kept buffering response data into memory, risking OOM on
  constrained platforms.
• Make the badCertificateCallback pinning test deterministic by pinning a
  fingerprint that cannot match the served certificate, instead of relying on
  badssl.com hosts serving different certificates.
• Fix NoSuchMethodError when using a class that implements Interceptor
  instead of extends Interceptor. The interceptor pipeline was calling private
  dispatch methods that only exist on Interceptor subclasses, breaking any
  class using interface implementation.