Fix typo: DeepSpeed in large_model_training.md

[lshmouse]

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Motivation

Fix typo: DeepSpeed in large_model_training.md

Modification

Fix typo: DeepSpeed in large_model_training.md

BC-breaking (Optional)

Does the modification introduce changes that break the backward-compatibility of the downstream repos?
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Use cases (Optional)

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Checklist

1. Pre-commit or other linting tools are used to fix the potential lint issues.
2. The modification is covered by complete unit tests. If not, please add more unit test to ensure the correctness.
3. If the modification has potential influence on downstream projects, this PR should be tested with downstream projects, like MMDetection or MMPretrain.
4. The documentation has been modified accordingly, like docstring or example tutorials.

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