compatibility: backport mercurial 176d1a0ce385 Backport obsstore.relevantmarkers change for including previously forgotten pruned obs markers. Target mercurial version lesser than 4.3. This impact multiple tests. All test changes has been manually checked. Since the computation of relevant obsmarkers have changed, we are bumping the cache schema version. So that caches get recomputed.

test-drop.t
test-inhibit.t
test-simple4server.t
tests/test-simple4server-bundle2.t