nixos/wpa_supplicant: prefer 'install' over 'touch/chmod/mkdir/chgrp'

[bjornfor]

Motivation for this change

Ref #121293.

Untested.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• 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 nixpkgs-review --run "nixpkgs-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.

[dotlambda]

Is there a downside to overwriting the group of an existin directory? Maybe we should keep this but put it before the install.

[bjornfor]

Is there a downside to overwriting the group of an existin directory?

I don't know. I'm not really familiar with wpa_supplicant. I tested if ACLs are preserved with install, and they are.

My thinking:

Old code: configure dir once and fail if group ownership differs later.
New code: configure dir always. (The code will only fail if there is insufficient permissions to configure things.)

I don't see any benefit of the old code. The new one automates something the old code would require user action to solve.

[iblech]

Thank you for your work, @bjornfor! On a superficial reading, your change looks good to me -- however, I currently don't have the time to think this through properly or to test this change. Sorry!

[dotlambda]

Let's merge in a couple of days if no one objects.

[rnhmjoj]

I don't see any problem with the new code, too. Let's merge this.