fix(nix/writers/rust): remove args override

We can be closed world, so let’s restrict the arguments to the subset
we need for now.

The existing override was wrong, in that `// args` would use the
arguments we already added, again. So instead of deliberating about
how to make this work right in all cases, we don’t need it, we trim
it.

Change-Id: I6443a0808b8bfd5e4db939b669c6afc741954db8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/3057
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>

users/Profpatsch/netencode/default.nix

@@ -7,8 +7,6 @@ let
         depot.third_party.rust-crates.nom
         depot.users.Profpatsch.execline.exec-helpers
       ];
-      release = false;
-      verbose = true;
     } (builtins.readFile ./netencode.rs);
 
   gen = import ./gen.nix { inherit lib; };