Clean up optimized-oss.yaml (#8668)

Pull Request resolved: https://github.com/pytorch/executorch/pull/8549

We don't need this now that we support log_softmax and gelu in OSS!
ghstack-source-id: 268149465
@exported-using-ghexport

Differential Revision: [D69475020](https://our.internmc.facebook.com/intern/diff/D69475020/)

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Co-authored-by: Scott Wolchok <swolchok@meta.com>