[IMP] Propose Odoo as default version for recent version to avoid useless consumption of CI

[legalsylvain]

Fix: #244

CC : @yajo, @sbidoul

[pedrobaeza]

#244 (comment)

[yajo]

FWIW this is just changing the default, which means that all repos will stay as they are now unless manually changed.

OTOH, whenever we branch off 18.0, these will default to only use Odoo, which makes sense because there'll be no known difference with OCB at the day of launch.

In general I agree with this, as explained in the issue. Thanks!

[github-actions]

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[carmenbianca]

Agree that electricity savings outweigh the borderline needs of testing against both all the time.

Odoo (instead of OCB) is a good default, but I could be convinced both ways.

If we absolutely must test against both versions, we should exclusively do so on the main branch, not on the PRs, and also not on the ocabot branch.

[OCA-git-bot]

This PR has the approved label and has been created more than 5 days ago. It should therefore be ready to merge by a maintainer (or a PSC member if the concerned addon has no declared maintainer). 🤖