Reapply "gss: re-enable tests"

Two in-flight PRs (NixOS#327128 and NixOS#328673) both solved the same problem in
a different way. This merges the best of both PRs and re-enables tests.

This reverts commit e850cbb.

The original commit was accidentally merged to master instead of
staging.

pkgs/development/libraries/gss/default.nix

@@ -13,7 +13,9 @@ stdenv.mkDerivation rec {
     url = "mirror://gnu/gss/gss-${version}.tar.gz";
     hash = "sha256-7M6r3vTK4/znIYsuy4PrQifbpEtTthuMKy6IrgJBnHM=";
   };
-  # This test crashes now.  Most likely triggered by expiration on 20240711.
+
+  # krb5context test uses certificates that expired on 2024-07-11.
+  # Reported to bug-gss@gnu.org with Message-ID: <87cyngavtt.fsf@alyssa.is>.
   postPatch = ''
     rm tests/krb5context.c
   '';
@@ -29,10 +31,6 @@ stdenv.mkDerivation rec {
     "--${if withShishi then "enable" else "disable"}-kerberos5"
   ];
 
-  # krb5context test uses certificates that expired on 2024-07-11.
-  # Reported to bug-gss@gnu.org with Message-ID: <87cyngavtt.fsf@alyssa.is>.
-  doCheck = !withShishi;
-
   # Fixup .la files
   postInstall = lib.optionalString withShishi ''
     sed -i 's,\(-lshishi\),-L${shishi}/lib \1,' $out/lib/libgss.la