[Backport 2025.4] feature(rolling-upgrades): update the base versions rules

[scylladbbot]

now that we have at least 4 short terms versions a year, we should now support upgrade from any of the STS version up to the last LTS version.

this gonna make the matrix more complex as we have more version between every LTS version

Testing

• 🟢 https://jenkins.scylladb.com/job/scylla-staging/job/fruch/job/rolling-upgrade-ubuntu2404-test/13/pipeline-overview/ (master)
• 🟢 : https://jenkins.scylladb.com/job/scylla-staging/job/fruch/job/rolling-upgrade-ubuntu2404-test/14/pipeline-overview/ (upgrade to release 2025.4)

PR pre-checks (self review)

• I added the relevant backport labels
• I didn't leave commented-out/debugging code

Reminders

• Add New configuration option and document them (in sdcm/sct_config.py)

• Add unit tests to cover my changes (under unit-test/ folder)

• Update the Readme/doc folder relevant to this change (if needed)

• (cherry picked from commit 9434f48)

Parent PR: #11959