[ARM][Settings][CmdNotFound]Fix CmdNotFound page init (#32892)

On ARM, process does not inherit environment, so PATH variable only contains SYSTEM values.
As pwsh.exe path is in USER PATH, check requirements script on CmdNotFound page load will fail
and as a result all requirements will be shown as missing.

Therefore, on loading, we manually set PATH variable, same as we do after installing pwsh7.

src/settings-ui/Settings.UI/ViewModels/CmdNotFoundViewModel.cs

@@ -58,6 +58,9 @@ private void InitializeEnabledValue()
                 _enabledStateIsGPOConfigured = true;
             }
 
+            // Update PATH environment variable to get pwsh.exe on further calls.
+            Environment.SetEnvironmentVariable("PATH", (Environment.GetEnvironmentVariable("PATH", EnvironmentVariableTarget.Machine) ?? string.Empty) + ";" + (Environment.GetEnvironmentVariable("PATH", EnvironmentVariableTarget.User) ?? string.Empty), EnvironmentVariableTarget.Process);
+
             CheckCommandNotFoundRequirements();
         }