Stack from ghstack:

• Kill defaults in nn.yaml. #25737 Kill defaults in nn.yaml.
• Kill 'default_init', which isn't needed anymore. #25717 Kill 'default_init', which isn't needed anymore.
• Kill cpu_zero in THFormal. #25712 Kill cpu_zero in THFormal.
• Kill declared_type and ignore_check from THFormal. #25655 Kill declared_type and ignore_check from THFormal.
• Kill if_true / if_false in Declarations.cwarp. #25615 Kill if_true / if_false in Declarations.cwarp.
• Replace simple if_true / if_false cases in Declarations.cwrap. #25614 Replace simple if_true / if_false cases in Declarations.cwrap.
• Kill aten_custom_call. #25613 Kill aten_custom_call.
• Kill remaining defaults in Declarations.cwrap. #25612 Kill remaining defaults in Declarations.cwrap.
• Get rid of more defaults in Declarations.cwrap. #25611 Get rid of more defaults in Declarations.cwrap.
• Kill most defaults in Declarations.cwrap. #25610 Kill most defaults in Declarations.cwrap.

Differential Revision: D17210038