Bump black (#4468)

Bumps [black](https://github.com/psf/black) from 25.1.0 to 26.3.1.
- [Release notes](https://github.com/psf/black/releases)
- [Changelog](https://github.com/psf/black/blob/main/CHANGES.md)
- [Commits](psf/black@25.1.0...26.3.1)

---
updated-dependencies:
- dependency-name: black
  dependency-version: 26.3.1
  dependency-type: direct:production
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

community-content/vertex-distributed-training/a3mega/llama-3-8b-nemo-pretraining/requirements.txt

@@ -1,7 +1,7 @@
 absl-py==2.2.2
 annotated-types==0.7.0
 anyio==4.9.0
-black==25.1.0
+black==26.3.1
 cachetools==5.5.2
 certifi==2025.4.26
 charset-normalizer==3.4.2