pip-rest: bump msal from 1.25.0 to 1.31.1 in /client-samples/python/rest

Bumps [msal](https://github.com/AzureAD/microsoft-authentication-library-for-python) from 1.25.0 to 1.31.1.
- [Release notes](https://github.com/AzureAD/microsoft-authentication-library-for-python/releases)
- [Commits](AzureAD/microsoft-authentication-library-for-python@1.25.0...1.31.1)

---
updated-dependencies:
- dependency-name: msal
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

client-samples/python/rest/requirements.txt

@@ -1 +1 @@
-msal==1.25.0
+msal==1.31.1