In particular, this gets rid of the `narHash` query parameter and
shortens the Git revision in GitHub flakerefs. So instead of
… from call site
at «github:NixOS/nixpkgs/3bea86e918d8b54aa49780505d2d4cd9261413be?narHash=sha256-Ica%2B%2BSXFuLyxX9Q7YxhfZulUif6/gwM8AEQYlUxqSgE%3D»/lib/customisation.nix:69:16:
68| let
69| result = f origArgs;
| ^
70|
we get
… from call site
at «github:NixOS/nixpkgs/3bea86e»/lib/customisation.nix:69:16:
68| let
69| result = f origArgs;
| ^
70|
This has already been implemented in 1e709554d5
as a side-effect of mounting the accessors in storeFS. Let's test this so it
doesn't regress.
(cherry-picked from https://github.com/NixOS/nix/pull/12915)