conduit-async: fix bounds for async

[samoht]

Should fix the issue found in #12552

[camelus]

✅ All lint checks passed 5a7ec80

• These packages passed lint tests: cohttp-async.1.0.0, cohttp-async.1.0.2, horned_worm.0.3.2

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✅ Installability check (9301 → 9301)

[samoht]

I'm moved some of the revdeps fixes to #12556 to avoid saturating the CI..

[mseri]

Let’s re run the tests with the sedlex and flow fixes

[samoht]

Rebased

[mseri]

Travis failures are few and all timeouts due to the high number of packages built and tested.
The CI failure are all infrastructure related, so I think we can merge

[samoht]

so I think we can merge

sounds good to me :-)