[new release] mirage-flow (3 packages) (4.0.2)

[hannesm]

Flow implementations and combinators for MirageOS

• Project page: https://github.com/mirage/mirage-flow
• Documentation: https://mirage.github.io/mirage-flow/

CHANGES:

• move Mirage_flow.stats and pp_stats to Mirage_flow_combinators (documentation updates mirage/mirage-flow#51 @hannesm)
• improve documentation of expected semantics (when write promise is resolved,
  what is done to the underlying flow - addresses Clarify the semantics of Flow.write when the buffer is full mirage/mirage-flow#4 @samoht),
  (documentation updates mirage/mirage-flow#51 @reynir @dinosaure @hannesm)
• revert < coercion, shutdown is again
  shutdown : flow -> [ `read | `write | `read_write ] -> unit Lwt.t
  (@reynir @hannesm)

[hannesm]

CI failures are unrelated, good to merge.

[mseri]

Thanks