perlPackages.mimeConstruct: add passthru.binlore

Consider this Nix expression:

  let
    pkgs = import /path/to/nixpkgs { };
  in

  pkgs.resholve.writeScript "mime-construct-binlore-test" {
    inputs = [ pkgs.perlPackages.mimeConstruct ];
    interpreter = "${pkgs.lib.getExe pkgs.bash}";
  } ''
    mime-construct --version
  ''

Before this change, that expression would fail to build because resholve
thought that mime-construct might be able to execute its arguments. This
commit fixes that problem.

pkgs/top-level/perl-packages.nix

@@ -15794,6 +15794,11 @@ with self; {
       description = "Construct and optionally mail MIME messages";
       license = with lib.licenses; [ gpl2Plus ];
     };
+    # Nothing in mime-construct --help or mime-construct’s man page mentions
+    # anything about mime-construct executing its arguments.
+    passthru.binlore.out = pkgs.binlore.synthesize self.perlPackages.mimeConstruct ''
+      execer cannot bin/mime-construct
+    '';
   };
 
   MIMEEncWords = buildPerlPackage {