Upgrade bitcoind-async-client to 0.8.1

[arminsabouri]

And off my personal fork

Drafting for now. Looks like bitcoin-async-client uses reqwest with the http2 feature flag (h2 is not used from what I can tell upstream) and this causes our reqwest clients to send http2 payloads. The dir only serves http1 reqs. Need to debug further. Should be able to just require our reqwest clients in the e2e and int. tests to use http1 only.

---- e2e::send_receive_payjoin_v2 stdout ----
OHTTP relay binding to port [::]:45663
2025-12-29T14:54:29.375932Z ERROR payjoin_directory: Error serving connection: hyper::Error(Parse(VersionH2))

thread 'e2e::send_receive_payjoin_v2' (98110) panicked at payjoin-cli/tests/e2e.rs:218:9:
send_receive failed: "Bad request"
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

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Update: updated all reqwest clients to use http1 explictly.

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[coveralls]

Pull Request Test Coverage Report for Build 20577112052

Details

• 12 of 13 (92.31%) changed or added relevant lines in 4 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.001%) to 82.903%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
payjoin/src/core/io.rs	1	2	50.0%

Totals
Change from base Build 20575392805:	0.001%
Covered Lines:	9669
Relevant Lines:	11663

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💛 - Coveralls

[benalleng]

Nice, I believe other than uniffi-dart this is our last dep pointed to a commit rev, one step closer to 1.0!

About forcing http1 should we also force this in the ohttp-relay? reqwest was added here payjoin/ohttp-relay@7bda6bd

Or is it only a problem as bitcoind-async-client already has the http2 feature forced thus requiring the explicit use of http1 where it is referenced

[arminsabouri]

Nice, I believe other than uniffi-dart this is our last dep pointed to a commit rev, one step closer to 1.0!

About forcing http1 should we also force this in the ohttp-relay? reqwest was added here payjoin/ohttp-relay@7bda6bd

Or is it only a problem as bitcoind-async-client already has the http2 feature forced thus requiring the explicit use of http1 where it is referenced

The latter
I don't think we need to force it on the relay. Its probably already defaulting to http1.

[spacebear21]

utACK baf60d4

FWIW supporting HTTP2 in the directory has been discussed here and is tracked as part of #941