Remove test_out, test_variant_consistency_eager skips for `addmv`; fixed before (#61579)
Summary:
This PR:
1. Removes `test_out` skip: it's not needed anymore after it was fixed in https://github.com/pytorch/pytorch/pull/55746. This should also close https://github.com/pytorch/pytorch/issues/55589.
2. Removes `test_variant_consistency_eager` skip, it was added by mistake in https://github.com/pytorch/pytorch/issues/55771.
3. Refines `sample_inputs_addmv` function, the updated function should now be cleaner and easy to read.
cc: mruberry
Pull Request resolved: https://github.com/pytorch/pytorch/pull/61579
Reviewed By: gchanan
Differential Revision: D29709674
Pulled By: mruberry
fbshipit-source-id: 9b975c024777efdd33c6b9444b0b36e0eab85c03
