Samples use unsupported WindowsAppSDK releases

As per the Windows App SDK release servicing policy, Windows App SDK releases prior to 1.7 are out of support, but there's still lots of 1.5 usage:

> findstr /spim /c:"Microsoft.WindowsAppSDK.1.5" *.vcxproj
DynamicDependenciesSample\DynamicDependencies\DirectX\D3D9ExSample.vcxproj
Samples\AppLifecycle\Activation\cpp\cpp-console-unpackaged\CppWinRtConsoleActivation\CppWinRtConsoleActivation.vcxproj
Samples\AppLifecycle\Activation\cpp\cpp-win32-packaged\CppWinMainActivation\CppWinMainActivation.vcxproj
Samples\AppLifecycle\Activation\cpp\cpp-win32-unpackaged\CppWinMainActivation\CppWinMainActivation.vcxproj
Samples\AppLifecycle\Activation\cpp\cpp-winui-packaged\CppWinUiDesktopActivation\CppWinUiDesktopActivation\CppWinUiDesktopActivation.vcxproj
Samples\AppLifecycle\EnvironmentVariables\cpp-console-unpackaged\CppWinRtConsoleEnv\CppWinRtConsoleEnv.vcxproj
Samples\AppLifecycle\EnvironmentVariables\cpp-win32-unpackaged\CppWinMainEnv\CppWinMainEnv.vcxproj
Samples\AppLifecycle\Instancing\cpp\cpp-console-unpackaged\CppWinRtConsoleInstancing\CppWinRtConsoleInstancing.vcxproj
Samples\AppLifecycle\Instancing\cpp\cpp-win32-packaged\CppWinMainInstancing\CppWinMainInstancing.vcxproj
Samples\AppLifecycle\Instancing\cpp\cpp-win32-unpackaged\CppWinMainInstancing\CppWinMainInstancing.vcxproj
Samples\AppLifecycle\Instancing\cpp\cpp-winui-packaged\CppWinUiDesktopInstancing\CppWinUiDesktopInstancing\CppWinUiDesktopInstancing.vcxproj
Samples\AppLifecycle\Restart\cpp-console-unpackaged\cpp-console-unpackaged.vcxproj
Samples\AppLifecycle\RestartRegistration\cpp-winui-packaged\cpp-winui-packaged.vcxproj
Samples\AppLifecycle\StateNotifications\cpp\cpp-console-unpackaged\CppWinRtConsoleState\CppWinRtConsoleState.vcxproj
Samples\AppLifecycle\StateNotifications\cpp\cpp-win32-packaged\CppWinMainState\CppWinMainState.vcxproj
Samples\AppLifecycle\StateNotifications\cpp\cpp-win32-unpackaged\CppWinMainState\CppWinMainState.vcxproj
Samples\AppLifecycle\StateNotifications\cpp\cpp-winui-packaged\CppWinUiDesktopState\CppWinUiDesktopState\CppWinUiDesktopState.vcxproj
Samples\Composition\DynamicRefreshRateTool\cpp-winui\DynamicRefreshRateTool.vcxproj
Samples\CustomControls\CppApp\CppApp.vcxproj
Samples\CustomControls\CppAppUnpackaged\CppAppUnpackaged.vcxproj
Samples\DeploymentManager\cpp-winui\DeploymentManagerSample.vcxproj
Samples\Insights\cpp-win32\InsightsSample.vcxproj
Samples\Mica\cpp-WebView2\Mica-WebView2\MicaWebView2.vcxproj
Samples\Mica\cpp-win32\WinAppSDKMicaSample\WinAppSDKMicaSample.vcxproj
Samples\Notifications\App\CppUnpackagedAppNotifications\CppUnpackagedAppNotifications\CppUnpackagedAppNotifications.vcxproj
Samples\Notifications\Push\cpp-console-packaged\cpp-console.vcxproj
Samples\Notifications\Push\cpp-console-unpackaged\cpp-console-unpackaged.vcxproj
Samples\PhotoEditor\cpp-winui\PhotoEditor\PhotoEditor.vcxproj
Samples\ResourceManagement\cpp\cpp-console-unpackaged\console_unpackaged_app.vcxproj
Samples\ResourceManagement\cpp\cpp-winui\winui_desktop_packaged_app_cpp\winui_desktop_packaged_app_cpp.vcxproj
Samples\SelfContainedDeployment\cpp\cpp-console-unpackaged\SelfContainedDeployment.vcxproj
Samples\SelfContainedDeployment\cpp\cpp-winui-packaged\SelfContainedDeployment.vcxproj
Samples\SelfContainedDeployment\cpp\cpp-winui-unpackaged\SelfContainedDeployment.vcxproj
Samples\TextRendering\cpp-win32\DWriteCoreGallery\DWriteCoreGallery.vcxproj
Samples\Unpackaged\cpp-console-unpackaged\Unpackaged.vcxproj
Samples\Widgets\cpp-win32-packaged\SampleWidgetProviderApp\SampleWidgetProviderApp.vcxproj
Samples\Windowing\cpp\cpp-winui\SampleApp\SampleApp.vcxproj

Start with the .vcxproj paths listed in the issue and rerun the provided findstr search for Microsoft.WindowsAppSDK.1.5. Determine the supported replacement from the Windows App SDK servicing policy, update every listed project reference, and verify that the search finds no remaining 1.5 usage.