Bump transformers from 4.26.1 to 4.38.0 in /examples/tensorflow/language-modeling-tpu (#31837)

Bump transformers in /examples/tensorflow/language-modeling-tpu

Bumps [transformers](https://github.com/huggingface/transformers) from 4.26.1 to 4.38.0.
- [Release notes](https://github.com/huggingface/transformers/releases)
- [Commits](https://github.com/huggingface/transformers/compare/v4.26.1...v4.38.0

)

---
updated-dependencies:
- dependency-name: transformers
  dependency-type: direct:production
...
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examples/tensorflow/language-modeling-tpu/requirements.txt

-transformers==4.26.1
+transformers==4.38.0
 datasets==2.9.0
 tokenizers==0.13.2