Align TargetPlatformVersion to 10.0.26100.0 for UWP

Make sure we're targeting the latest supported Windows SDK across all platforms, it still has min target of 17763 (1809) which is also supported by the tooling, docs: https://developer.microsoft.com/windows/downloads/windows-sdk/

Author: michael-hawker

MultiTarget/Extra.props

@@ -8,8 +8,7 @@
     -->
     <TargetPlatformMinVersion>10.0.17763.0</TargetPlatformMinVersion>
     <SupportedOSPlatformVersion>$(TargetPlatformMinVersion)</SupportedOSPlatformVersion>
-    <TargetPlatformVersion Condition="'$(MultiTargetPlatformIdentifier)' == 'windows'">10.0.26100.0</TargetPlatformVersion>
-    <TargetPlatformVersion Condition="'$(MultiTargetPlatformIdentifier)' != 'windows'">10.0.19041.0</TargetPlatformVersion>
+    <TargetPlatformVersion>10.0.26100.0</TargetPlatformVersion>
 
     <Platforms>x86;x64;arm64</Platforms>
   </PropertyGroup>
@@ -37,4 +36,4 @@
     <!--- Workaround for ADO 53865998 - See https://github.com/CommunityToolkit/Tooling-Windows-Submodule/issues/215 - Don't include extraneous WebView2 dll -->
     <WebView2NeverCopyLoaderDllToOutputDirectory>true</WebView2NeverCopyLoaderDllToOutputDirectory>
   </PropertyGroup>
-</Project>
+</Project>