CmdPal: Ensure cached window data is refreshed when the window style changes (#42405)

## Summary of the Pull Request

This PR resolves the issue where the window style WS_EX_TOOLWINDOW was
being set but not properly applied to the window.

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## PR Checklist

- [x] Closes: #42395
- [ ] **Communication:** I've discussed this with core contributors
already. If the work hasn't been agreed, this work might be rejected
- [ ] **Tests:** Added/updated and all pass
- [ ] **Localization:** All end-user-facing strings can be localized
- [ ] **Dev docs:** Added/updated
- [ ] **New binaries:** Added on the required places
- [ ] [JSON for
signing](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ESRPSigning_core.json)
for new binaries
- [ ] [WXS for
installer](https://github.com/microsoft/PowerToys/blob/main/installer/PowerToysSetup/Product.wxs)
for new binaries and localization folder
- [ ] [YML for CI
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ci/templates/build-powertoys-steps.yml)
for new test projects
- [ ] [YML for signed
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/release.yml)
- [ ] **Documentation updated:** If checked, please file a pull request
on [our docs
repo](https://github.com/MicrosoftDocs/windows-uwp/tree/docs/hub/powertoys)
and link it here: #xxx

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## Detailed Description of the Pull Request / Additional comments

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## Validation Steps Performed

src/modules/cmdpal/Microsoft.CmdPal.UI/Helpers/WindowExtensions.cs

@@ -51,7 +51,12 @@ internal static class WindowExtensions
             currentStyle &= ~(int)style;
         }
 
-        return PInvoke.SetWindowLong(hWnd, WINDOW_LONG_PTR_INDEX.GWL_EXSTYLE, currentStyle) != 0;
+        var wasSet = PInvoke.SetWindowLong(hWnd, WINDOW_LONG_PTR_INDEX.GWL_EXSTYLE, currentStyle) != 0;
+
+        // SWP_FRAMECHANGED - invalidate cached window style
+        PInvoke.SetWindowPos(hWnd, new HWND(IntPtr.Zero), 0, 0, 0, 0, SET_WINDOW_POS_FLAGS.SWP_FRAMECHANGED | SET_WINDOW_POS_FLAGS.SWP_NOMOVE | SET_WINDOW_POS_FLAGS.SWP_NOSIZE | SET_WINDOW_POS_FLAGS.SWP_NOZORDER | SET_WINDOW_POS_FLAGS.SWP_NOOWNERZORDER);
+
+        return wasSet;
     }
 
     /// <summary>