8365219d40
This PR adds the upgrade guide from version 2025.2 to 2025.3. Also, it removes the upgrade guide existing for the previous version that is irrelevant in 2025.2 (upgrade from 2025.1 to 2025.2). Note that the new guide does not include the "Enable Consistent Topology Updates" page and note, as users upgrading to 2025.3 have consistent topology updates already enabled. Fixes https://github.com/scylladb/scylladb/issues/24696 Closes scylladb/scylladb#25219