go-camo: link nixos test

pkgs/by-name/go/go-camo/package.nix

@@ -3,6 +3,7 @@
   buildGo124Module,
   fetchFromGitHub,
   installShellFiles,
+  nixosTests,
   scdoc,
 }:
 
@@ -43,6 +44,10 @@ buildGo124Module rec {
     rm pkg/camo/proxy_{,filter_}test.go
   '';
 
+  passthru.tests = {
+    inherit (nixosTests) go-camo;
+  };
+
   meta = {
     description = "Camo server is a special type of image proxy that proxies non-secure images over SSL/TLS";
     homepage = "https://github.com/cactus/go-camo";