... because explicit language=None causes the below warning since
Sphinx 5.0.0.
Invalid configuration value found: 'language = None'. Update your
configuration to a valid language code. Falling back to 'en' (English).
Change-Id: Ieca6a2cb9724346ed4ee40a20335a02d737a3cd4
Remove all deprecated hooks and tests.
Also since all test and hooks are removed,
we can remove the declare of python language in classifier.
Since we didn't actually provide any document,
we should remove docs too.
Hooks are maintained as Agents under heat-agents repo now.
Hooks in heat-templates are deprecated for a while. Hence, remove
hooks in heat-templates.
Depends-On: https://review.openstack.org/#/c/584774/
Change-Id: Ia886f71eaf99d75db0f9a6a7dfbe8664995c26e7