This commit fixes the product names in the upgrade 2025.1 guides so that:
- 6.2 is preceded with "ScyllaDB Open Source"
- 2024.x is preceded with "ScyllaDB Enterprise"
- 2025.1 is preceded with "ScyllaDB"
Fixes https://github.com/scylladb/scylladb/issues/23154
Closes scylladb/scylladb#23223
(cherry picked from commit cd61f60549)
Closes scylladb/scylladb#23328