copies-sdc: no longer suppress the upgrade output To make sure the upgrade simplification we need are taken into account, we need to see more of the output of `debugupgraderepo`. The --quiet flag simplify the output a lot and globing the `preserved` field mean this output should remains stable across (future) unrelated changes.

copies-sdc: no longer use revlogv2 in `test-copies-in-changeset.t` We only need changelog-v2 and its usage is automatically inferred. So we can simplify the test by dropping this. This is important to test future simplification of the update process in the coming changesets.

fix-ci: backed out changeset 308e45f7b455 The chg variant of the CI see a failure on `tests/test-narrow-pull.t`. Bisecting point the failure as starting at this small changeset… Backing it out, restore the CI on default. It was never broken on stable, which is even more puzzling.

branching: merge stable into default

branching: merge with stable

rust-repo: make `Send` by not storing functions in `LazyCell` We (Google) want to use `Repo` in a context where we can store it in `Mutex<Repo>`. However, that currently doesn't work because it's not `Send` because the `LazyCell` initialization functions are not `Send`. It's easy to fix that by passing them to the `get_or_init()` and `get_mut_or_init()` functions. We'll probably also want `Repo` to be `Send` (and even `Sync`) in core later, so this seems like a step in the right direction. Differential Revision: https://phab.mercurial-scm.org/D12582

obsolete: remove two unused constants I'm not sure what these constants were intended for, but they have no users so it's time to say goodbye. Differential Revision: https://phab.mercurial-scm.org/D12609