Fix: Missing super().__del__() in Cycles and Hydra render engine

According to the Python API release notes, this is required now along
with super().__init__() which was already done.

Also fixes mistake in example in API docs.

Pull Request: https://projects.blender.org/blender/blender/pulls/132476

doc/python_api/rst/info_overview.rst

@@ -206,7 +206,7 @@ must always be called, otherwise Blender's internal initialization won't happen
 
       def __del__(self):
          ...
-         super.__del__()
+         super().__del__()
 
 .. note::
 

intern/cycles/blender/addon/__init__.py

@@ -55,6 +55,7 @@ class CyclesRender(bpy.types.RenderEngine):
 
     def __del__(self):
         engine.free(self)
+        super().__del__()
 
     # final render
     def update(self, data, depsgraph):

scripts/modules/bpy_types.py

@@ -1351,6 +1351,7 @@ class HydraRenderEngine(RenderEngine):
             if self.engine_ptr:
                 import _bpy_hydra
                 _bpy_hydra.engine_free(self.engine_ptr)
+        super().__del__()
 
     def get_render_settings(self, engine_type: str):
         """