RANGER-5126: Add coverage for testing ranger upgrades

[kumaab]

What changes were proposed in this pull request?

Adding an on-demand workflow to take input arguments and run ranger upgrades for pre-determined release branches with pre-determined ranger databases to the version passed during manual trigger.

This is helpful to test ranger upgrade path during release process.

How was this patch tested?

Triggered manually via command:

gh workflow run test-upgrade.yaml --ref ranger-upgrade-workflow --field release_branch="ranger-2.6"

Link to job: https://github.com/apache/ranger/actions/runs/13150138270