src/sage/graphs/generators: add pickled Golay code graph data

Add a pickled/xz'd list of vertices and edges for the Shortened 000
111 extended binary Golay code graph. It's much faster to construct
this graph from cached data than it is to do it on-the-fly.

Author: orlitzky

src/sage/graphs/generators/meson.build

@@ -10,6 +10,7 @@ py.install_sources(
   'intersection.py',
   'platonic_solids.py',
   'random.py',
+  'shortened_000_111_extended_binary_Golay_code_graph.pickle.xz',
   'smallgraphs.py',
   'world_map.py',
   subdir: 'sage/graphs/generators',