Bump haystack-ai from 2.1.2 to 2.3.1 (#1)

Bumps [haystack-ai](https://github.com/deepset-ai/haystack) from 2.1.2 to 2.3.1.
- [Release notes](https://github.com/deepset-ai/haystack/releases)
- [Commits](deepset-ai/haystack@v2.1.2...v2.3.1)

---
updated-dependencies:
- dependency-name: haystack-ai
  dependency-type: direct:production
...

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

requirements.txt

@@ -1,7 +1,7 @@
 torch==2.1.2
 transformers==4.42.3
 datasets==2.16.1
-haystack-ai==2.1.2
+haystack-ai==2.3.1
 qdrant-haystack
 evaluate==0.4.1
 peft==0.11.1