Cypress cannot see the `window.__coverage__` object

**Logs and screenshots**

**Versions**
- What is this plugin's version? If this is NOT the latest [released version](https://github.com/cypress-io/code-coverage/releases), can you try the latest version, please? `3.12.39` (latest)
- If the plugin worked before in version X but stopped after upgrading to version Y, please try the [released versions](https://github.com/cypress-io/code-coverage/releases) between X and Y to see where the breaking change was.
- What is the Cypress version? `13.10.0`
- What is your operating system? `MacOS`
- What is the shell? `OMZ`
- What is the Node version? `22.2.0`
- What is the NPM version? `10.7.0`
- How do you instrument your application? Cypress [does not instrument web application code](https://github.com/cypress-io/code-coverage#instrument-your-application), so you must do it yourself. `Using vite-plugin-istanbul`
- When running tests, if you open the web application in a regular browser and open DevTools, do you see `window.__coverage__` object? Can you paste a screenshot? `yes` (screenshot above)
- Is there a `.nyc_output` folder? Is there a `.nyc_output/out.json` file? Is it empty? Can you paste at least part of it so we can see the keys and file paths? `yes, but empty`
- Do you have any custom NYC settings in `package.json` (`nyc` object) or in other [NYC config files](https://github.com/istanbuljs/nyc#configuration-files)? `no`
- Do you run Cypress tests in a Docker container? `no`

**Describe the bug**
When launching E2E tests using Cypress with a nuxt 3 stack, I run into the following problem:
- The `window.__coverage__` object is preset (see screenshot), but Cypress does not manage to find it

**Link to the repo**
[Repro repo](https://github.com/Curs3W4ll/Cypress-code-coverage-bug-showcase)
```
npm install
npm run test:e2e:dev
```