Remove '.' entry

Having an explicit folder in the tar that is named "." causes it to do
bad things to the current directory and its permissions when it is
unpacked. It also introduces an extra level of effort not needed. So
let's not do that

flake.nix

@@ -69,7 +69,7 @@
                 installPhase = ''
                   mkdir -p $out
                   pushd ${win.sword}
-                  ${pkgs.gnutar}/bin/tar cvhaf $out/sword.tar.xz .
+                  ${pkgs.gnutar}/bin/tar cvhaf $out/sword.tar.xz *
                 '';
               };
             };