Simplify element state by removing `__cached`

Description

I encountered a build failure while using workspaces where the artifact was simultaneously cached and not.

I didn't track down exactly why it was getting confused, but simplifying the state made the problem go away.

Changes proposed in this merge request:

• Remove __cached variable.
• Replace users of it with checking which of __strong_cached or __weak_cached to use instead.

CHANGELOG/Release Notes

• Initial version

approved this merge request

mentioned in issue #410

added 56 commits

• 723e7c21...3b81d451 - 55 commits from branch master
• 55956762 - element: Remove __cached field

Compare with previous version

enabled an automatic merge when the pipeline for 55956762 succeeds

merged

mentioned in commit fc7f83ac