[ARM][Installer]Fix UninstallCommandNotFoundModule not finding pwsh(#33143)

* [ARM][Installer] Fix UninstallCommandNotFoundModule

On ARM, processes does not inherit the user env variables. So, pwsh.exe could not be found from installer process.
Logic is changed to use powershell.exe to first set process' PATH env var and then trigger pwsh.exe

* address PR comments

Author: stefansjfw

installer/PowerToysSetupCustomActions/CustomAction.cpp

@@ -608,9 +608,19 @@ UINT __stdcall UninstallCommandNotFoundModuleCA(MSIHANDLE hInstall)
     hr = getInstallFolder(hInstall, installationFolder);
     ExitOnFailure(hr, "Failed to get installFolder.");
 
+#ifdef _M_ARM64
+    command = "powershell.exe";
+    command += " ";
+    command += "-NoProfile -NonInteractive -NoLogo -WindowStyle Hidden -ExecutionPolicy Unrestricted";
+    command += " -Command ";
+    command += "\"[Environment]::SetEnvironmentVariable('PATH', [Environment]::GetEnvironmentVariable('PATH', 'Machine') + ';' + [Environment]::GetEnvironmentVariable('PATH', 'User'), 'Process');";
+    command += "pwsh.exe -NoProfile -NonInteractive -NoLogo -WindowStyle Hidden -ExecutionPolicy Unrestricted -File '" + winrt::to_string(installationFolder) + "\\WinUI3Apps\\Assets\\Settings\\Scripts\\DisableModule.ps1" + "'\"";
+#else
     command = "pwsh.exe";
     command += " ";
     command += "-NoProfile -NonInteractive -NoLogo -WindowStyle Hidden -ExecutionPolicy Unrestricted -File \"" + winrt::to_string(installationFolder) + "\\WinUI3Apps\\Assets\\Settings\\Scripts\\DisableModule.ps1" + "\"";
+#endif
+
 
     system(command.c_str());