Always use `WfdMetaConfigCacheFactory` to enable checks of wfd-meta-ConfigCacheResourceCheckers? (Case 171239)

[MalteWunsch]

Currently, the WebfactoryWfdMetaExtension loads:

• cache_busting.yml if always_expire_wfd_meta_resources is set, which configures CacheBustingResourceChecker as a service and tags it as config_cache.resource_checker
• config_cache_factory.xml ONLY if always_expire_wfd_meta_resources is not set. This decorates Symfonys config_cache_factory service with a WfdMetaConfigCacheFactory, which checks a chache's freshness with their registered wfd-meta-ConfigCacheResourceCheckers, too.

Problem is that always_expire_wfd_meta_resources does not enable the WfdMetaConfigCacheFactory and in turn prevents checks of any wfd-meta-ConfigCacheResourceCheckers at all, at least with production settings. (The fact that one probably shouldn't use this configuration setting in production is another story.)

Additional question: Does the cache busting work only under certain circumstances, e.g. kernel debug mode, or not at all?

A possible solution is to do the decoration in both cases. This should not break anything, as the decoration already happened always, before the always_expire_wfd_meta_resources config setting was introduced in c7a2e2b.

References: https://github.com/webfactory/krankenkassen/pull/862