Bump azure-core from 1.35.0 to 1.38.0 in /user-auth/graphtutorial

Bumps [azure-core](https://github.com/Azure/azure-sdk-for-python) from 1.35.0 to 1.38.0.
- [Release notes](https://github.com/Azure/azure-sdk-for-python/releases)
- [Commits](Azure/azure-sdk-for-python@azure-core_1.35.0...azure-core_1.38.0)

---
updated-dependencies:
- dependency-name: azure-core
  dependency-version: 1.38.0
  dependency-type: indirect
...

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

Author: dependabot[bot]

user-auth/graphtutorial/requirements.txt

@@ -16,7 +16,7 @@ async-timeout==5.0.1
     # via aiohttp
 attrs==25.3.0
     # via aiohttp
-azure-core==1.35.0
+azure-core==1.38.0
     # via
     #   azure-identity
     #   microsoft-kiota-authentication-azure
@@ -129,8 +129,6 @@ requests==2.32.5
     # via
     #   azure-core
     #   msal
-six==1.17.0
-    # via azure-core
 sniffio==1.3.1
     # via anyio
 std-uritemplate==2.0.5