Add Zygote.jl to PySR env

pysr/juliapkg.json

@@ -12,6 +12,10 @@
         "Serialization": {
             "uuid": "9e88b42a-f829-5b0c-bbe9-9e923198166b",
             "version": "1"
+        },
+        "Zygote": {
+            "uuid": "e88e6eb3-aa80-5325-afca-941959d7151f",
+            "version": "0.6"
         }
     }
 }