We can remove the non-virtual dropConnections functions in the derived classes since they're already in the base class.

Currently, the dropConnections functions have two versions (targeted and untargeted). There is also potential to collapse them to one function by representing the target as a nullable pointer. This should technically only affect the base class and its derived classes and not the callsites. The down-side is that it could potentially make the API harder to understand so we should discuss this proposal and see if this is a viable option for us.

Please refer to this discussion for more context: https://github.com/10gen/mongo/pull/36942#discussion_r2138869532