[1.x] Remove VariationCache dependency, for Drupal 10.2 update

This is not yet correct and functional in this form, the patch needs to be revised/extended.

Yeah, we're actively calling classes from the variationcache namespace. I already released a final VariationCache version that should work with core before and after 10.2 as long as modules are stuck using the old contrib namespace for BC reasons. I'll see if I can safely remove VC in v2/v3 but it may have to wait until v4.

Also this is a job for Flexible Permissions as Group no longer relies on variation cache and Group v1 no longer gets any updates aside from security fixes or sponsored work. So going to close this one as won't fix. Feel free to open an issue in the FP issue queue, though, which will indirectly benefit Group v2 and v3.

ClaudiuVisan → changed the visibility of the branch 3409374-1.x-remove-variationcache to hidden.

ClaudiuVisan → changed the visibility of the branch 3409374-1.x-remove-variationcache to active.