Bump azure-storage-blob from 12.17.0 to 12.20.0

Bumps [azure-storage-blob](https://github.com/Azure/azure-sdk-for-python) from 12.17.0 to 12.20.0.
- [Release notes](https://github.com/Azure/azure-sdk-for-python/releases)
- [Changelog](https://github.com/Azure/azure-sdk-for-python/blob/main/doc/esrp_release.md)
- [Commits](Azure/azure-sdk-for-python@azure-storage-blob_12.17.0...azure-storage-blob_12.20.0)

---
updated-dependencies:
- dependency-name: azure-storage-blob
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

requirements.txt

@@ -2,7 +2,7 @@ azure-identity==1.15.0
 # Flask[async]==2.3.2
 openai==1.6.1
 azure-search-documents==11.4.0b6
-azure-storage-blob==12.17.0
+azure-storage-blob==12.20.0
 python-dotenv==1.0.0
 azure-cosmos==4.5.0
 quart==0.19.4