git-annex: wrap with lsof

Required by the assistant at runtime:

```
$ nix-shell --pure -p git git-annex
$ git annex assistant
git-annex: The lsof command is needed for watch mode to be safe, and is not in PATH.
To override lsof checks to ensure that files are not open for writing
when added to the annex, you can use --force
Be warned: This can corrupt data in the annex, and make fsck complain.
```

pkgs/development/haskell-modules/configuration-nix.nix

@@ -548,7 +548,7 @@ self: super: builtins.intersectAttrs super {
     # where non-GNU coreutils are used by default.
     postFixup = ''
       wrapProgram $out/bin/git-annex \
-        --prefix PATH : "${pkgs.lib.makeBinPath [ pkgs.coreutils ]}"
+        --prefix PATH : "${pkgs.lib.makeBinPath (with pkgs; [ coreutils lsof ])}"
     '' + (drv.postFixup or "");
     buildTools = [
       pkgs.buildPackages.makeWrapper