[iOS] Add `LibTorch-Lite-Nightly` pod (#63239)
Summary:
D30090760 (https://github.com/pytorch/pytorch/commit/e182b459d94fe77c1d9f623c94fc2621c8cc55de) was reverted by D30303292 because of a lint issue in `LibTorch-Lite-Nightly.podspec.template`. Resubmit the diff after fixing the issue.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/63239
Test Plan: Imported from OSS
Reviewed By: xta0
Differential Revision: D30315690
Pulled By: hanton
fbshipit-source-id: f0fa719ffc3b8181ab28c123584ae5c1da8992c0
