Prune deleted and unresolvable configurations from single lock file

[ljacomet]

The topic of non longer existing configurations has always been a discussion in the context of dependency locking.

Because of its potential for dynamic addition of configurations, Gradle cannot really automate cleaning up stale lock state for configurations that no longer exist in the build.
With one lockfile per configuration per project, manually deleting stale files was not such a big issue.

However with the single lockfile format, introduced in #11881, it becomes more complicated as manual edits of the file are not recommended.

So Gradle should provide a system for pruning stale configurations from that lock file.

[big-guy]

Configurations that still exist but are no longer resolvable are also candidates for removal.

e.g., in 7.6, the default configuration was considered resolvable (but deprecated) and may have appeared in lock files.

In 8.0, the default configuration is no longer resolvable, but still exists.