fix(core): convert absolute file path to file URL in locateElectronExecutable

[erikian]

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• The changes are appropriately documented (if applicable).
• The changes have sufficient test coverage (if applicable).
• The testsuite passes successfully on my local machine (if applicable).

Summarize your changes:

This prevents the following error when running electron-forge start on Windows:

Error [ERR_UNSUPPORTED_ESM_URL_SCHEME]: Only URLs with a scheme in: file, data, and node are supported by the default ESM loader. On Windows, absolute paths must be valid file:// URLs. Received protocol 'c:'

Testing

• on a Windows machine, run yarn spawn-verdaccio to start the Verdaccio local registry
• create a project using the local version of create-electron-app with $env:NPM_CONFIG_REGISTRY="http://127.0.0.1:4873"; node ./packages/external/create-electron-app/dist/create-electron-app.js vite-esm-test --template=vite-typescript
• start the project with cd vite-esm-test ; yarn electron-forge start; it should launch the app correctly (on the next branch, I get the error mentioned above instead)
• there should be no changes on macOS or Linux