Upgrade to Microsoft.WindowsAppSDK 1.8.260508005

[JunielKatarn]

Description

Homologates WinAppSDK versions in both CI agents and NuGet assets.

Type of Change

• Bug fix (non-breaking change which fixes an issue)

Why

CI agents install the latest Win App SDK which may make older NuGet package versions incompatible.

What

Bumps package Microsoft.WindowsAppSDK version to 1.8.260508005.

CI loops were showing an obscure message about a component version mismatch:

ERROR: DEP0800: The required framework "D:\a\_work\_temp\.nuget\packages\microsoft.windowsappsdk.runtime\1.8.260209005\buildTransitive\..\tools\MSIX\win10-x86\Microsoft.WindowsAppRuntime.1.8.msix" failed to install. [0x80073D06] Windows cannot install package Microsoft.WindowsAppRuntime.1.8_8000.770.947.0_x86__8wekyb3d8bbwe because it has version 8000.770.947.0. A higher version 8000.859.21.0 of this package is already installed.

See https://dev.azure.com/ms/8d8e50dd-c5b4-4b44-8668-86558c5aa5b7/_apis/build/builds/631108/logs/1952

Based on the NuGet package's metadata for recent 1.8.x versions, the version mapping is the following:

1.8.250907003 -> 8000.616.304.0
1.8.250916003 -> 8000.625.330.0
1.8.251003001 -> 8000.642.119.0
1.8.251106002 -> 8000.675.1142.0
1.8.260101001 -> 8000.731.1532.0
1.8.260209005 -> 8000.770.947.0
1.8.260317003 -> 8000.806.2252.0
1.8.260416003 -> 8000.836.2153.0
1.8.260508005 -> 8000.859.21.0

Microsoft Reviewers: Open in CodeFlow