fix:docs build errors

[bhimrazy]

What does this PR do?

Unblocks other PRs by fixing documentation build failures.

• Added ("py:data", "typing.Union") to nitpick_ignore in:

  • docs/source-fabric/conf.py
  • docs/source-pytorch/conf.py

• Fixed broken linkcheck (403) for Supermicro Gaudi.

Did you have fun?

Make sure you had fun coding 🙃

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📚 Documentation preview 📚: https://pytorch-lightning--21286.org.readthedocs.build/en/21286/

[github-actions]

⚡ Required checks status: All passing 🟢

Groups summary

🟢 fabric: Docs

Check ID	Status
docs-make (fabric, doctest)	success	✅
docs-make (fabric, html)	success	✅

These checks are required after the changes to docs/source-fabric/conf.py.

🟢 pytorch_lightning: Docs

Check ID	Status
docs-make (pytorch, doctest)	success	✅
docs-make (pytorch, html)	success	✅

These checks are required after the changes to docs/source-pytorch/conf.py.

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Thank you for your contribution! 💜

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[bhimrazy]

Merging this PR — the GPU test failure is unrelated to this PR and appears to be affecting other PRs as well. We’ll investigate that issue separately.

cc: @ethanwharris @tchaton