Remove useless pieces of code in update of space groups, but keep the…

… things that should stay...

gflownet/envs/crystals/spacegroup.py

@@ -727,36 +727,24 @@ def _restrict_space_groups(self, sg_subset: Optional[Iterable] = None):
             del self.point_symmetries[ps]
 
         # Update self.crystal_lattice_systems based on point symmetries
-        cls_to_remove = []
         point_symmetries = set(self.point_symmetries)
         for cls in self.crystal_lattice_systems:
             cls_point_symmetries = point_symmetries.intersection(
                 set(self.crystal_lattice_systems[cls]["point_symmetries"])
             )
-            if len(cls_point_symmetries) == 0:
-                cls_to_remove.append(cls)
-            else:
-                self.crystal_lattice_systems[cls]["point_symmetries"] = list(
-                    cls_point_symmetries
-                )
-        for cls in cls_to_remove:
-            del self.crystal_lattice_systems[cls]
+            self.crystal_lattice_systems[cls]["point_symmetries"] = list(
+                cls_point_symmetries
+            )
 
-        # Update self.point_symmetries based on point symmetries
-        ps_to_remove = []
+        # Update self.point_symmetries based on crystal lattice systems
         crystal_lattice_systems = set(self.crystal_lattice_systems)
         for ps in self.point_symmetries:
             ps_crystal_lattice_systems = crystal_lattice_systems.intersection(
                 set(self.point_symmetries[ps]["crystal_lattice_systems"])
             )
-            if len(ps_crystal_lattice_systems) == 0:
-                ps_to_remove.append(ps)
-            else:
-                self.point_symmetries[ps]["crystal_lattice_systems"] = list(
-                    ps_crystal_lattice_systems
-                )
-        for ps in ps_to_remove:
-            del self.point_symmetries[ps]
+            self.point_symmetries[ps]["crystal_lattice_systems"] = list(
+                ps_crystal_lattice_systems
+            )
 
     def get_all_terminating_states(
         self, apply_stoichiometry_constraints: Optional[bool] = True