v324: Release swh.alter 0.1.0

Includes:

• swh.storage 2.5.0
  • only contains changes to the deletion interface, which is not used by anything other than swh.alter (it's not even RPC-able)
  • (no commit for that as I canceled the build when I noticed the objstorage release, ❄ 🐻 👍🏻)
• swh.storage 2.6.0
  • adds an implicit flush() on destruction of the buffer proxy
  • updates the postgresql deletion to avoid corrupting snapshots
• swh.objstorage 3.2.0
  • contains the ability for the http client to retry requests automatically (off by default)
• swh.alter 0.1.0
  • with a train of updates including our recent changes (and usage of the swh.storage 2.5.0 methods)
• swh.loader.core 5.18.2, swh.loader.mercurial & swh.loader.git updates
  • Pulls snapshots from the same visit type for incremental visits, and ancillary fixes