octavePackages.geometry: fix build of octave environment by adding top-level gsl library

pkgs/development/octave-modules/geometry/default.nix

@@ -3,6 +3,7 @@
   lib,
   fetchurl,
   matgeom,
+  gsl,
 }:
 
 buildOctavePackage rec {
@@ -18,6 +19,10 @@ buildOctavePackage rec {
     matgeom
   ];
 
+  buildInputs = [
+    gsl
+  ];
+
   meta = {
     homepage = "https://gnu-octave.github.io/packages/geometry/";
     license = with lib.licenses; [