Update Ceph to v19.2.3

[simu]

Summary

We've done a fairly extensive performance evaluation for Ceph v19 and have not found any significant performance regressions compared to Ceph v18.

The PR also disables bluestore_elastic_shared_blobs which should ensure that OSDs that are created with Ceph v19 don't crash, cf. https://docs.clyso.com/blog/critical-bugs-ceph-reef-squid/#squid-deployed-osds-are-crashing.

NOTE: Rolling back the upgrade from Ceph v18 to Ceph v19 isn't supported out of the box, since downgrading the MONs to v18 causes them to crash with

debug 2026-02-12T08:44:35.741+0000 7f9bc2d08bc0 -1 ERROR: on disk data includes unsupported features: compat={},rocompat={},incompat={16=squid ondisk layout}
debug 2026-02-12T08:44:35.741+0000 7f9bc2d08bc0 -1 error checking features: (1) Operation not permitted

Checklist

• The PR has a meaningful title. It will be used to auto-generate the
  changelog.
  The PR has a meaningful description that sums up the change. It will be
  linked in the changelog.
• PR contains a single logical change (to build a better changelog).
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  bug, enhancement, documentation, change, breaking, dependency
  as they show up in the changelog.

[github-actions]

🚀 Merging this PR will release v9.0.0

Merging will trigger workflows Release

🛠️ Auto tagging enabled with label bump:major