phases: incrementally update the phase sets when reasonable When the amount of manual walking is small, we update the phases set manually instead of computing them from scratch. This should help small update. The next changesets will make this used more often by reducing the amount of full invalidation we do on roots upgrade. The criteria for using an incremental upgrade are arbitrary, however, it "should never hurt".

phasees: properly shallow caopy the phase sets dictionary We are about to increments the set more incrementally in some case, so we need to make a proper shallow copy of it.

phases: pass an unfiltered repository to _ensure_phase_sets It seems better for such a low level function to be able to assume it operate on a real repository.

phases: drop set building in `hasnonpublicphases` We don't actually use the set, so why do we ensure they are built? (we should also clean up the use of repository argument but that's a quest for later).

phases: gather the logic for phasesets update in a single method This logic is duplicated around for no good reason, we gather it in a single place. The conditional is the new function are a bit weird as we about going to extend it soon.

phases: change the way we warm the phasecache in repocache Same logic as for the previous chngeset. We are about to rename and change the method used here.

phases: use a more generic way to trigger a phases computation for perf Querying the tip most revision will require the cache to warm the same as calling the dedicated method. This avoid using a method that is mostly meant for internal use and will be renamed in a coming changesets.

phases: fix an overzealous invalidation of the phase sets If `len(cl) == self._loadedrevslen` the cache is up to date.

phases: type annotation for `_phasesets` Does not hurt.

phases: leverage the collected information to record phase update Since the lower level function already gather this information, we can directly use it. This comes with a small change to the test that are actually fixing them. The previous version over-reported some phase change that did not exists. In both case, we are force revision `1` to be secret and `0` remains draft`, the previous code wrongly reported `0` as moving to secret while it properly remained draft in the repository.