Merge branch 'ps/maintenance-geometric'

"git maintenance" command learns the "geometric" strategy where it avoids doing maintenance tasks that rebuilds everything from scratch. * ps/maintenance-geometric: t7900: fix a flaky test due to git-repack always regenerating MIDX builtin/maintenance: introduce "geometric" strategy builtin/maintenance: make "gc" strategy accessible builtin/maintenance: extend "maintenance.strategy" to manual maintenance builtin/maintenance: run maintenance tasks depending on type builtin/maintenance: improve readability of strategies builtin/maintenance: don't silently ignore invalid strategy builtin/maintenance: make the geometric factor configurable builtin/maintenance: introduce "geometric-repack" task builtin/gc: make `too_many_loose_objects()` reusable without GC config builtin/gc: remove global `repack` variable