Bump pygments in /ai/gen-ai-agents/custom-rag-agent/files

Bumps [pygments](https://github.com/pygments/pygments) from 2.19.1 to 2.20.0.
- [Release notes](https://github.com/pygments/pygments/releases)
- [Changelog](https://github.com/pygments/pygments/blob/master/CHANGES)
- [Commits](pygments/pygments@2.19.1...2.20.0)

---
updated-dependencies:
- dependency-name: pygments
  dependency-version: 2.20.0
  dependency-type: direct:production
...

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Author: dependabot[bot]

ai/gen-ai-agents/custom-rag-agent/files/requirements.txt

@@ -153,7 +153,7 @@ pydantic==2.11.7
 pydantic-settings==2.8.1
 pydantic_core==2.33.2
 pydeck==0.9.1
-Pygments==2.19.1
+Pygments==2.20.0
 PyJWT==2.10.1
 pylint==3.3.4
 PyMuPDF==1.25.4