Auto merge of #52986 - pietroalbini:beta-backports, r=Mark-Simulacrum
[beta] Rollup backports & switch bootstrap compiler
This PR switches the bootstrap compiler from dev-static to static, and rollups some backports.
Merged and approved:
* #52929: Update compatibility note for 1.28.0 to be correct
* #52918: Backport 1.27.2 release notes
* #52867: releases.md: fix 2 typos
* #52996: RELEASES.md: fix the `hash_map::Entry::or_default` link
r? @Mark-Simulacrum