Issue/8052 make get or else backward compatible

[Hugo-Inmanta]

Description

Follow-up to https://github.com/inmanta/inmanta-core/pull/8109/files#diff-ad2bbfb0ef3fc86910ef80ee69791b16f3b8c78491912c25f3edaa3a651deb43

The previous implementation didn't take into account the necessity for the get_or_else method to be backwards compatible wrt the for_version and timeout arguments.

Slack discussion: https://inmanta.slack.com/archives/CKRF0C8R3/p1727851998216269

Self Check:

Strike through any lines that are not applicable (~~line~~) then check the box

- [ ] Attached issue to pull request

• [x] Changelog entry
• [x] Type annotations are present
• [x] Code is clear and sufficiently documented
• [x] No (preventable) type errors (check using make mypy or make mypy-diff)
• [x] Sufficient test cases (reproduces the bug/tests the requested feature) - [ ] Correct, in line with design - [ ] End user documentation is included or an issue is created for end-user documentation (add ref to issue here: ) - [ ] If this PR fixes a race condition in the test suite, also push the fix to the relevant stable branche(s) (see test-fixes for more info)

[inmantaci]

Processing this pull request

[inmantaci]

Merged into branches master in e15a8b3c51e466ad7d7a1a456c9e321529b67ae0