Update `GPTNeoXLanguageGenerationTest`
# What does this PR do?

Due to the changes in [EleutherAI/pythia-410m-deduped](https://huggingface.co/EleutherAI/pythia-410m-deduped/commits/main), we have to update the output value, despite the new value doesn't look great 😭 

(The previous revisions seem to disappear ...I  guess they rewrite the commit history on their Hub repo) 
_The documentation is not available anymore as the PR was closed or merged._<|||||>The docs for this PR live [here](https://moon-ci-docs.huggingface.co/docs/transformers/pr_24193). All of your documentation changes will be reflected on that endpoint.