leatherman: fix build w/glibc-2.34

Failing Hydra build: https://hydra.nixos.org/build/155215198

pkgs/development/libraries/leatherman/default.nix

···
     owner = "puppetlabs";
   };
 
+  cmakeFlags = [ "-DLEATHERMAN_ENABLE_TESTING=OFF" ];
+
   NIX_CFLAGS_COMPILE = "-Wno-error";
 
   nativeBuildInputs = [ cmake ];