This PR:
- Adds the upgrade guide from ScyllaDB Open Source 5.4 to ScyllaDB Enterprise 2024.1. Note: The need to include the "Restore system tables" step in rollback has been confirmed; see https://github.com/scylladb/scylladb/issues/11907#issuecomment-1842657959.
- Removes the 5.1-to-2022.2 upgrade guide (unsupported versions).
Fixes https://github.com/scylladb/scylladb/issues/16445Closesscylladb/scylladb#16887
* github.com:scylladb/scylladb:
doc: fix the OSS version number
doc: metric updates between 2024.1. and 5.4
doc: remove the 5.1-to-2022.2 upgrade guide
doc: add the 5.4-to-2024.1 upgrade guide
(cherry picked from commit edb983d165)