Cannot run update hook 8006 with core 8.5 because of 8.6 dependency

Using drupal core 8.5 I cannot execute the facets_update_8006().

drush updatedb shows the update info "Update facet blocks configuration with a block id used for AJAX support" (taken from the description of facets_update_8006) but the function is never called.

I digged a little deeper and found:

• the dependency check introduced in #3006741 checks for the update of core module block_content 8600 (facets_update_dependencies())
• update block_content 8600 is part of drupal 8.6 but not of 8.5
  (update number 8600 -> core 8.6)
• So facets_update_dependencies() blocks the execution of facets_update_8006() until block_content update 8600 is performed - which is never!
• So facets_update_8006() is never executed!
• and the next drush updatedb will show facets_update_8006 again and again!

See hook_update_N() and hook_update_dependencies().

So I think we need some check for the drupal version in facets_update_dependencies().