fossil: cleanup tests

pkgs/applications/version-management/fossil/default.nix

···
   nativeBuildInputs = [ tcl ];
 
   doCheck = stdenv.hostPlatform == stdenv.buildPlatform;
-
-  checkTarget = "test";
-
-  preCheck = stdenv.lib.optional doCheck ''
+  preCheck = ''
     export TCLLIBPATH="${tcllib}/lib/tcllib${tcllib.version}"
   '';
   configureFlags = stdenv.lib.optional withJson "--json";