Update microsoft-graph.md

[omondiatieno]

Update alert to indicate that Azure AD Graph is in its retirement phase.

[learn-build-service-prod[bot]]

Learn Build status updates of commit 7e6207c:

:warning: Validation status: warnings

File	Status	Preview URL	Details
docs-ref-services/legacy/microsoft-graph.md	:warning:Warning	View (azure-python-previous)	Details

docs-ref-services/legacy/microsoft-graph.md

• Line 2, Column 1: [Warning: ms-prod-missing - See documentation] Missing attribute: 'ms.prod'. If you specify 'ms.technology', you must also specify 'ms.prod'.
• Line 6, Column 12: [Suggestion: ms-author-invalid - See documentation] Invalid value for 'ms.author', 'ramyar' is not a valid Microsoft alias.

For more details, please refer to the build report.

Note: Your PR may contain errors or warnings or suggestions unrelated to the files you changed. This happens when external dependencies like GitHub alias, Microsoft alias, cross repo links are updated. Please use these instructions to resolve them.

For any questions, please:

• Try searching the learn.microsoft.com contributor guides
• Post your question in the Learn support channel

[omondiatieno]

#sign-off

[omondiatieno]

#sign-off