Update LegacyBrowserAuthProtocolsEnabled setting to reflect the ongoing deprecation

[jenniferpeled]

This PR adds a note to the LegacyBrowserAuthProtocolsEnabled that warns that the protocol is being deprecated in Oct 2025 and will no longer be available. Since the deprecation is multiple phases, and not all customers will be blocked until late 2026, we cannot yet completely remove the setting, but will once possible.

[learn-build-service-prod]

PoliCheck Scan Report

The following report lists PoliCheck issues in PR files. Before you merge the PR, you must fix all severity-1 issues. Other issues are also a high priority. The AI Review Details column lists suggestions for either removing or replacing the terms. If you find a false positive result, mention it in a PR comment and include this text: #policheck-false-positive. This feedback helps reduce false positives in future scans.

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[learn-build-service-prod]

Learn Build status updates of commit 69a414e:

✅ Validation status: passed

File	Status	Preview URL	Details
sharepoint/sharepoint-ps/Microsoft.Online.SharePoint.PowerShell/Set-SPOTenant.md	✅Succeeded	View (sharepoint-ps)

For more details, please refer to the build report.

[samkabue]

[learn-build-service-prod]

Learn Build status updates of commit 22953ca:

✅ Validation status: passed

File	Status	Preview URL	Details
sharepoint/sharepoint-ps/Microsoft.Online.SharePoint.PowerShell/Set-SPOTenant.md	✅Succeeded	View (sharepoint-ps)

For more details, please refer to the build report.

[learn-build-service-prod]

PoliCheck Scan Report

The following report lists PoliCheck issues in PR files. Before you merge the PR, you must fix all severity-1 issues. Other issues are also a high priority. The AI Review Details column lists suggestions for either removing or replacing the terms. If you find a false positive result, mention it in a PR comment and include this text: #policheck-false-positive. This feedback helps reduce false positives in future scans.

✅ No issues found

More information about PoliCheck

Information: PoliCheck | Severity Guidance | Term
For any questions: Try searching the learn.microsoft.com contributor guides or post your question in the Learn support channel.