Merge branch 'ps/geometric-repacking-with-promisor-remotes' into jch

Merge branch 'ps/geometric-repacking-with-promisor-remotes' into jch

"git repack --geometric" did not work with promisor packs, which
has been corrected.

* ps/geometric-repacking-with-promisor-remotes:
  builtin/repack: handle promisor packs with geometric repacking
  repack-promisor: extract function to remove redundant packs
  repack-promisor: extract function to finalize repacking
  repack-geometry: extract function to compute repacking split
  builtin/pack-objects: exclude promisor objects with "--stdin-packs"