Allow calling functorch transforms when their DispatchKeys are disabled (#100011)
This was always the intended behavior: e.g. you should be able to call
functorch.functionalize even when DispatchKey::Functionalize is
disabled.
Test Plan:
- new tests
Pull Request resolved: https://github.com/pytorch/pytorch/pull/100011
Approved by: https://github.com/tugsbayasgalan
