Nightly Windows: 3 Go workspace unit tests fail (Unix-only GOWORK paths) #1815

Nightly CI on main (run 40824880386, job test (windows-latest, 1)) fails -p socket-patch-core --lib with 3 of 6536 tests failing. These are deterministic assertion failures, not flakes. They came in with #1763 / #1764 (merged 2026-10-28). PR CI and the merge queue don't run the Windows test matrix, so the queue never saw them.

vendor::go_workspace::tests::gowork_resolves_as_go_does  (go_workspace.rs:1141)
  left:  Invalid("GOWORK=/elsewhere/go.work is not an absolute path, so go refuses to build …")
  right: File("/elsewhere/go.work")

vex::discover::golang::tests::gowork_naming_another_workspace_attests_nothing  (golang.rs:1848)
  /nonexistent/go.work: [Diag { code: "patched_ref_invalid", … GOWORK=/nonexistent/go.work is not an absolute path … }]

vendor::go_workspace::tests::a_workspace_module_is_never_replaced  (go_workspace.rs:1479)
  MainModule { work_file: "\\\\?\\C:\\Users\\runneradmin\\AppData\\Local\\Temp\\.tmpSk8aez\\ws\\go.work", member: "\\\\?\\C:\\…\\ws\\dep" }

Likely fix (test side): build the GOWORK fixtures from a tempdir or another absolute path that works on each platform instead of /elsewhere and /nonexistent. For the third test, compare paths after stripping the verbatim prefix (or canonicalize both sides), or find out where \\?\ comes from (a canonicalize on Windows). Open PRs #1812 and #1800 touch both files, so the janitor didn't change them this run. Whoever lands next should check these tests on Windows (workflow_dispatch of CI).

The cargo-home half of the same nightly failure is fixed in #1814.