[PowerToys Run] Update to net5 (#12434)

* [Setup] Add support for installing both dotnet 3 and 5 (#12306)

* [PowerToys Run] Update to net5 (#12286)

* Change targets of projects

* Update Microsoft.Toolkit.Uwp.Notifications,

changed TargetFramework for PowerLauncher project in order to resolve an issue with ModernWpf

* Specify windows version in order to fix build errors

* Fixed suppressed warnings

* Updated sdk

* Removed usage of obsolete GlobalAssemblyCache

* Removed obsolete DesktopNotificationManagerCompat

* Update nuget versions

* Update installer

* [PowerToys Run] Obsolete APIs and warnings introduced in .net5 (#12423)

* Change targets of projects

* Update Microsoft.Toolkit.Uwp.Notifications,

changed TargetFramework for PowerLauncher project in order to resolve an issue with ModernWpf

* Fixed suppressed warnings

* Removed obsolete DesktopNotificationManagerCompat

* Get rid of binary formatter

* Update tests

* Don't include new image cache file to the report

* There's no need to call IsOwner as it doesn't make sense

* Fix different nullability exception

* Exclude extra dlls from tests

Co-authored-by: Andrey Nekrasov <yuyoyuppe@users.noreply.github.com>

src/modules/launcher/Plugins/Microsoft.PowerToys.Run.Plugin.WindowsSettings/Helper/ResultHelper.cs

@@ -103,7 +103,7 @@ namespace Microsoft.PowerToys.Run.Plugin.WindowsSettings.Helper
             if (command.Contains(' '))
             {
                 var commandSplit = command.Split(' ');
-                var file = commandSplit.FirstOrDefault();
+                var file = commandSplit.FirstOrDefault() ?? string.Empty;
                 var arguments = command[file.Length..].TrimStart();
 
                 processStartInfo = new ProcessStartInfo(file, arguments)

src/modules/launcher/Plugins/Microsoft.PowerToys.Run.Plugin.WindowsSettings/Helper/UnsupportedSettingsHelper.cs

@@ -65,7 +65,7 @@ namespace Microsoft.PowerToys.Run.Plugin.WindowsSettings.Helper
         /// <returns>A registry value or <see cref="uint.MinValue"/> on error.</returns>
         private static uint GetNumericRegistryValue(in string registryKey, in string valueName)
         {
-            object registryValueData;
+            object? registryValueData;
 
             try
             {