[DOC][14.0] describe how to write queue.job.function in case of function defined in abstract model

[legalsylvain]

Context

• having an abstract model (mixin) with a function to be delayed.
• inherit in many models.

Expected behaviour

• write a queue.job.function with the abstract model should work and catch the correct channel.

Current behaviour

• we have to write a queue.job.function per model. Otherwise, the match is not done, and job is affected to root channel.

This PR just explicits the current behaviour of queue_job module.

CC : FYI, @guewen

Note : I have the problem in V12, but i think more relevant to fix the doc upstream)

[dreispt]

/ocabot merge patch

[OCA-git-bot]

What a great day to merge this nice PR. Let's do it!
Prepared branch 14.0-ocabot-merge-pr-362-by-dreispt-bump-patch, awaiting test results.

[OCA-git-bot]

Congratulations, your PR was merged at 218ad56. Thanks a lot for contributing to OCA. ❤️