Update troubleshoot-windows-365-boot.md

[kev-out]

added an additional troubleshooting step :
when user has multiple cloud pcs and has no default cloud pc set
"something went wrong" will be also displayed on login before user has selected a default pc on windows365.microsoft.com

validated these steps on Windows 11 Enterprise 23H2 - OS Build 22631.3880

[prmerger-automator]

@kev-out : Thanks for your contribution! The author(s) have been notified to review your proposed change.

[learn-build-service-prod]

Learn Build status updates of commit 5709b58:

✅ Validation status: passed

File	Status	Preview URL	Details
windows-365/enterprise/troubleshoot-windows-365-boot.md	✅Succeeded

For more details, please refer to the build report.

For any questions, please:

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

[learn-build-service-prod]

Learn Build status updates of commit 3b48224:

✅ Validation status: passed

File	Status	Preview URL	Details
windows-365/enterprise/troubleshoot-windows-365-boot.md	✅Succeeded

For more details, please refer to the build report.

For any questions, please:

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

[ErikjeMS]

#sign-off