Bump msal from 1.26.0 to 1.28.0 in /model-engine

Bumps [msal](https://github.com/AzureAD/microsoft-authentication-library-for-python) from 1.26.0 to 1.28.0.
- [Release notes](https://github.com/AzureAD/microsoft-authentication-library-for-python/releases)
- [Commits](AzureAD/microsoft-authentication-library-for-python@1.26.0...1.28.0)

---
updated-dependencies:
- dependency-name: msal
  dependency-type: indirect
...

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

Author: dependabot[bot]