lnwallet: fix lnwallet test compilation on v0.20.x

[ziggie1984]

The lnwallet test package does not compile on this branch, which fails CI for every PR targeting it, regardless of that PR's own contents.

lnwallet/wallet_test.go:6:2: no required module provides package
  github.com/lightningnetwork/lnd/chanstate

Cause

The regression test added by the backport of #11035 was taken verbatim from master, where the OpenChannel type lives in the chanstate package. That package does not exist on this branch. The cherry-pick applied without a conflict because the commit only adds an import line and a new function — there was nothing textual for git to reconcile — so the breakage landed silently.

The same problem exists on v0.21.x-branch, fixed identically in #11092.

Impact

Because the missing package is unresolvable in the module graph, this breaks considerably more than go test ./lnwallet:

Check	Failure
Run unit tests (all variants)	FAIL github.com/lightningnetwork/lnd/lnwallet [setup failed]
Check commits	no required module provides package .../chanstate
Lint code	could not load export data for ".../chanstate" → Makefile:378: lint-source Error 3
Cross compilation	no required module provides package → Makefile:199: release Error 1

make release and golangci-lint both resolve test imports, which is why even the build-only jobs fail.

Fix

Use channeldb.OpenChannel — the type completeChan actually carries on this branch (lnwallet/wallet.go:337, :366). Two lines; no production code touched.

Testing

• go vet ./... — clean (previously reported the error above)
• go build ./... — clean
• go test ./lnwallet/ -run TestHandleFundingCounterPartySigsMissingReservation — passes, having been uncompilable before

[github-actions]

🟢 PR Severity: LOW

gh pr view | 1 files | 4 lines changed

🟢 Low (1 files)

• lnwallet/wallet_test.go - test-only change, no production code touched

Analysis

Although lnwallet/* is normally a CRITICAL package (wallet operations, channel funding, signing), this PR only modifies wallet_test.go, a test file, with a very small diff (2 additions / 2 deletions). Per the classification rules, test-only changes are treated as LOW severity regardless of the package they live in, and no bump is warranted given the tiny, single-file diff.

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