Migrate Syncfusion Toolkit for .NET MAUI to .NET 9.0

[saiganesh-sakthivel]

Description:
This PR updates the Syncfusion Toolkit for .NET MAUI and its sample browser to officially support .NET 9.0 while maintaining compatibility with .NET 8.0. This migration ensures users can leverage the latest features and improvements of .NET 9.0.

Changes Made:

1. Target Framework Update:
   • The Syncfusion Toolkit for MAUI now officially supports .NET 9.0, while remaining compatible with .NET 8.0.
2. Package Updates:
   • Updated all dependencies to the latest versions compatible with .NET 9.0.
3. Code Adjustments:
   • Addressed API and compatibility changes introduced with .NET 9.0.
4. Sample Browser:
   • Updated the sample browser projects to reflect the framework migration.
   • Reviewed and updated all existing samples to ensure compatibility with .NET 9.0.

[PaulAndersonS]

/azp run

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[PaulAndersonS]

/azp run

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[PaulAndersonS]

/azp run

[azure-pipelines[bot]]

Azure Pipelines successfully started running 1 pipeline(s).