feat(saving-and-feedback): edit auto-save guidelines

Based on the learnings from gitlab-org/gitlab!167417 (comment 2140278369)

Although the Pajamas guidance explains that we should continue to retry saving until it succeeds, I do not think we should do this. This could lead the user into a continuous circle of failures. Retrying until succession makes more sense for saving drafts IMO. One could argue that including another Retry action is not necessary either since the user can just hit the toggle again.

this MR updates the auto-save guidelines to suggest only triggering a toast with a retry action when a change fails to save, rather than additionally automatically trying to save the change again. I'm proposing this because automatically trying to save the change again can lead the user in a continuous circle of failures.