Update quickstart-botframework-integration.md to use managed identity

[jimchou-dev]

Update instruction to switch to managed identity since multi-tenant will be deprecated on 2025-07-31

[prmerger-automator]

@jimchou-dev : Thanks for your contribution! The author(s) and reviewer(s) have been notified to review your proposed change.

[learn-build-service-prod]

Learn Build status updates of commit c8b75fd:

💡 Validation status: suggestions

File	Status	Preview URL	Details
articles/communication-services/quickstarts/chat/quickstart-botframework-integration.md	💡Suggestion		Details

articles/communication-services/quickstarts/chat/quickstart-botframework-integration.md

• Line 45, Column 256: [Suggestion: preserve-view-not-set - See documentation] You've pinned this link to a specific version of content with the view parameter. It's recommended not to pin a version unless that version is A) not the default view and B) the context is about that version specifically. To proceed with pinning a version add the &preserve-view=true to the URL. Otherwise, remove the view parameter. URL: /azure/bot-service/abs-quickstart?view=azure-bot-service-4.0&tabs=userassigned#to-update-your-app-service

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[v-regandowner]

@tariqzafa700 - Can you review the proposed changes?

IMPORTANT: When the changes are ready for publication, adding a #sign-off comment is the best way to signal that the PR is ready for the review team to merge.

#label:"aq-pr-triaged"
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