080950b0fe
This adds a test case where the lockfile of a relative path flake
dependency is updated.
It was reported by a user here: https://discourse.nixos.org/t/updating-local-subflakes-inputs-when-building-root-flake/61682
I think this test case relates to issue #7730.
Because the issue is not resolved, this test case would fail without
the `|| true` clause.
(cherry picked from commit 1bc82d1c86)