Do this if we want to do `--hash-algo` everywhere, and not `--algo` for hash commands. The new `nix hash convert` is updated. Deprecated new CLI commands are left as-is (`nix hash path` needs to be redone and is also left as-is).
The old syntax is still supported, as long as you don't use a { in the description - the reason to migrate.
nix hash convert
builtins.convertHash
https://github.com/NixOS/nix/issues/8876