hooks: invalidate the repo after the hooks Since the hooks may have changed the repository content it seems safer to invalidate it. The invalidation is "soft", the data are kept around and few work will be needed to restore them if nothing actually changed.

dirstate: try refreshing the changelog when parent are unknown See inline comment for details.

localrepo: add a `currentlock` method It mirrors he `currentwlock` function.

dirstate: add a test to highlight another changelog / dirstate race

rust: fix thread cap (for real this time) Both e2f8ed37201c and c52435820bbd failed to put a *default* ceiling on the number of threads used by Rayon to prevent a contention issue. Calling `rayon::available_parallelism()` creates the global threadpool, which made our whole dance useless last time.

tests: accept a test output change in [tests/test-serve.t] This fixes a breakage introduced in adecb1ab4a0d. It was not caught by the CI probably because allows binding to port 13.