Try to remove group_relationship list cache tags in group_entity_access()

Problem/Motivation

Background: in doing a performance audit for a site with groups module installed, I noticed that their main menu block had several group_relationship_list cache tags on it - the menu almost entirely contains links to nodes. This means the menu block (and dynamic page cache) is added whenever a group relationship is created for any node.

group_entity_access() has the following code:

  // If any new relationship entity is added using any of the retrieved
  // plugins, it might change access.
  $plugin_cache_tags = [];
  foreach ($plugin_ids as $plugin_id) {
    $plugin_cache_tags[] = "group_relationship_list:plugin:$plugin_id";
  }
  $access = AccessResult::neutral()->addCacheTags($plugin_cache_tags);

When saving a relationship for an entity, the cache tags for the entity itself are invalidated, this is also the case after #2872697: Stop saving an entity when it gets added to or removed from a group.

Given that, I think it should be OK to remove the list cache tags from group_entity_access() entirely, and rely on the invalidation of the entity cache tag instead. This would dramatically improve render cache hit rates on some sites if it's possible.

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes