build(deps): bump azure-identity from 1.21.0 to 1.23.0 in /backend

Bumps [azure-identity](https://github.com/Azure/azure-sdk-for-python) from 1.21.0 to 1.23.0.
- [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](https://github.com/Azure/azure-sdk-for-python/compare/azure-identity_1.21.0...azure-identity_1.23.0)

---
updated-dependencies:
- dependency-name: azure-identity
  dependency-version: 1.23.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

backend/requirements.txt

@@ -115,7 +115,7 @@ pytest-docker~=3.1.1
 googleapis-common-protos==1.63.2
 google-cloud-storage==2.19.0
 
-azure-identity==1.21.0
+azure-identity==1.23.0
 azure-storage-blob==12.24.1