gpclient: keep nixpkgs-update opt-out visible

In 344a3c2437 we attempted to disable bot updates on gpclient. But it
didn't work because of a quirk in bot logic.

Re-inherit the description locally so meta.position points at gpclient
while preserving the inherited metadata text.

Precedent: https://github.com/NixOS/nixpkgs/commit/fab23265d6c6678e49a0526d6111ac8a9c26fdc9

Assisted-by: gpt-5.5 xhigh

pkgs/by-name/gp/gpclient/package.nix

@@ -41,11 +41,15 @@ rustPlatform.buildRustPackage {
   # nixpkgs-update: no auto update
   inherit (gpauth)
     cargoHash
-    meta
     src
     version
     ;
 
+  meta = gpauth.meta // {
+    # Re-anchor meta.position here so nixpkgs-update sees the opt-out above.
+    inherit (gpauth.meta) description;
+  };
+
   buildAndTestSubdir = "apps/gpclient";
 
   nativeBuildInputs = [