refactor: remove dead modules/lib/fs.nix file

modules/lib/default.nix

@@ -3,7 +3,6 @@
 let
 sane-lib = rec {
   feeds = import ./feeds.nix { inherit lib; };
-  fs = import ./fs.nix { inherit lib sane-lib; };
   merge = import ./merge.nix { inherit lib sane-lib; };
   path = import ./path.nix { inherit lib; };
   types = import ./types.nix { inherit lib; };

modules/lib/fs.nix

@@ -1,33 +0,0 @@
-{ lib, sane-lib, ... }:
-
-let
-  sane-path = sane-lib.path;
-in rec {
-  # Type: derefSymlinkOrNull :: config.sane.fs.type -> str -> (str|null)
-  # the returned path is always absolute (even if the original symlink was relative),
-  # and in canonical form.
-  derefSymlinkOrNull = fs: logical: let
-    symlinkedPrefixes = lib.filter
-      (p: ((fs."${p}" or {}).symlink or null) != null)
-      (sane-path.walk "/" logical);
-    firstSymlink = builtins.head symlinkedPrefixes;
-    firstSymlinkDest = fs."${firstSymlink}".symlink.target;
-    firstSymlinkParent = sane-path.parent firstSymlink;
-    firstSymlinkDestAbs = if lib.hasPrefix "/" firstSymlinkDest then
-      firstSymlinkDest
-    else
-      sane-path.join [ firstSymlinkParent firstSymlinkDest ];
-  in
-    if symlinkedPrefixes != [] then
-      sane-path.realpath firstSymlinkDestAbs
-    else
-      null
-  ;
-  derefSymlink = fs: logical:
-    if derefSymlinkOrNull fs logical != null then
-      derefSymlinkOrNull fs logical
-    else
-      logical
-  ;
-}
-