Bump cryptography from 46.0.5 to 46.0.6 in /src/backend

Bumps [cryptography](https://github.com/pyca/cryptography) from 46.0.5 to 46.0.6.
- [Changelog](https://github.com/pyca/cryptography/blob/main/CHANGELOG.rst)
- [Commits](pyca/cryptography@46.0.5...46.0.6)

---
updated-dependencies:
- dependency-name: cryptography
  dependency-version: 46.0.6
  dependency-type: direct:production
...

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

Author: dependabot[bot]

src/backend/pyproject.toml

@@ -37,7 +37,7 @@ dependencies = [
     "agent-framework-orchestrations==1.0.0b260311",
     "urllib3==2.6.3",
     "protobuf==5.29.6",
-    "cryptography==46.0.5",
+    "cryptography==46.0.6",
     "aiohttp==3.13.3",
     "pyasn1==0.6.2",
     "nltk==3.9.3",