## Changes
1. Removes `DefaultMutatorsForTarget` which is no longer used anywhere
2. Makes SnapshotPath a private field. It's no longer needed by data
structures outside its package.
FYI, I also tried finding other instances of dead code but I could not
find anything else that was safe to remove. I used
https://go.dev/blog/deadcode to search for them, and the other instances
either implemented an interface, increased test coverage for some of our
other code paths or there was some other reason I could not remove them
(like autogenerated functions or used in tests).
Good sign our codebase is mostly clean (at least superficially).