poke: 1.2 -> 1.3

See https://lists.gnu.org/archive/html/info-gnu/2021-06/msg00001.html
and https://git.savannah.gnu.org/cgit/poke.git/tree/NEWS?h=releases/poke-1.3&id=5daa9ac5364d961629843e606c2a6744aac5df44
for release information.

pkgs/applications/editors/poke/default.nix

@@ -19,11 +19,11 @@ let
   isCross = stdenv.hostPlatform != stdenv.buildPlatform;
 in stdenv.mkDerivation rec {
   pname = "poke";
-  version = "1.2";
+  version = "1.3";
 
   src = fetchurl {
     url = "mirror://gnu/${pname}/${pname}-${version}.tar.gz";
-    hash = "sha256-9hz42ltkwBoTWTc3JarRyiV/NcHJJp5NUN0GZBg932I=";
+    hash = "sha256-unhjA0obCABLDuj4i9qUFgcH6aeB1VVvVVtQdYPPDxs=";
   };
 
   postPatch = ''