Inline script from layout doesn't run on not found page when using parallel routes

### Link to the code that reproduces this issue https://github.com/dmitrc/nextjs-packagelocalizationprovider-repro ### To Reproduce 1. Start the dev server (`next start` behaves the same way) 2. Navigate to /test and press "Check" button 3. Observe that a global value set from [LocalizedStringProvider](https://react-spectrum.adobe.com/react-aria/ssr.html#nextjs-app-router)'s script has been set <img width="572" height="287" alt="Image" src="https://github.com/user-attachments/assets/2440c087-3ba8-4f97-b5d0-72879c87aac1" /> 5. Now navigate to /zzz (that will 404) and press "Check" button 6. Observe that a global value set from [LocalizedStringProvider](https://react-spectrum.adobe.com/react-aria/ssr.html#nextjs-app-router)'s script has **NOT** been set <img width="660" height="309" alt="Image" src="https://github.com/user-attachments/assets/a1ac7650-cd36-45f1-aebd-8b3f17b7642a" /> 8. Search for `window[Symbol.for('react-aria.i18n.locale')]` in the DOM to find the relevant script (meaning it was rendered, but not executed) <img width="1341" height="352" alt="Image" src="https://github.com/user-attachments/assets/1001dd25-1899-42cb-a425-ed771057912d" /> 9. Now remove the parallel route by deleting `@modal` folder and corresponding layout slot 10. Restart the dev server 11. Repeat the test above, and observe that it works as expected now <img width="575" height="246" alt="Image" src="https://github.com/user-attachments/assets/c88bf1f5-dbe6-4b34-a03d-323d6c4b5452" /> ### Current vs. Expected behavior This issue is weird, but I was able to isolate it to the minimal repro linked above. ## Concepts React-Aria's [LocalizedStringProvider](https://react-spectrum.adobe.com/react-aria/ssr.html#nextjs-app-router) is a server-side component that writes a `<script>` which puts some strings in a global variable on `window`. This is normally included in the server-side layout output, and allows to optimize the client JS bundle by only pre-baking the strings for the specific locale th…