CSS/CSR objects are normally synchronized via the CSS mutex (which lives outside the objects themselves). However, components like the range deleter and state dumping (for serverStatus for example) access CSS/CSR pointers directly, bypassing normal synchronization.

In order to synchronize these accesses, we introduced the _metadataManagerLock mutex. However, the rules of when it should be used and what is safe to access without the CSS lock are a bit obscure to follow, so we should just remove it and instead rely on the regular acquisition path.