build(deps): Use self-maintained btcutil (#10082) (backport #10201)

[mergify]

This is an automatic backport of pull request #10201 done by Mergify.
Cherry-pick of 623d084 has failed:

On branch mergify/bp/release/v0.44.x/pr-10201
Your branch is up to date with 'origin/release/v0.44.x'.

You are currently cherry-picking commit 623d0841c.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   client/keys/show_test.go
	modified:   crypto/keys/secp256k1/secp256k1_test.go
	modified:   types/bech32/bech32.go
	modified:   x/authz/client/rest/grpc_query_test.go

Unmerged paths:
  (use "git add/rm <file>..." as appropriate to mark resolution)
	both modified:   go.mod
	both modified:   go.sum
	deleted by us:   x/group/go.mod
	deleted by us:   x/group/go.sum

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/github/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

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