KCL: Close polygon sketch (#9389)

Obviously a polygon profile is closed, but we forgot to set the is_closed property.

Author: adamchalmers

rust/kcl-lib/src/std/shapes.rs

@@ -521,6 +521,7 @@ async fn inner_polygon(
     };
 
     sketch.paths.push(current_path);
+    sketch.is_closed = ProfileClosed::Explicitly;
 
     exec_state
         .batch_modeling_cmd(

rust/kcl-lib/tests/kcl_samples/hex-nut-with-chamfer/program_memory.snap

@@ -889,8 +889,7 @@ description: Variables in memory after executing hex-nut-with-chamfer.kcl
       },
       "artifactId": "[uuid]",
       "originalId": "[uuid]",
-      "units": "mm",
-      "isClosed": "no"
+      "units": "mm"
     }
   },
   "holeRadius": {