Motivation for this change

Worktree locations were causing hash changes. With the name parameter you can avoid that.

To quote the new inline doc: We recommend setting name whenever src is syntactically ./.. Otherwise, you depend on ./.'s name in the parent directory, which can cause inconsistent names, defeating caching.

From the commit message

This change is API-compatible and hash-compatible with the previous
version.

At first I considered to write a rename function too, but adding
it name to cleanSourceWith was a no-brainer for ease of use. It
turns out that a rename function isn't any more useful than
cleanSourceWith.
To avoid having to write the identity predicate when renaming,
the filter is now optional.

builtins.path is supported since Nix 2.0 which is required by nixpkgs

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nix-review --run "nix-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.