fix: init when there's a package.json in folder

[thymikee]

Summary:

When init in a folder that contains any kind of package.json the failed with:

error Failed to load configuration of your project.

This is due to reactNativeVersion introduced in #1870 accessing the initialConfig.reactNativePath getter, which throws in situations where there's no package.json file available in the directory. Reading this in finalConfig is fine, because when there's no package.json, it skips the logic inside the .reduce, which accesses initialConfig.reactNativePath variable.

Tbh, this is rather convoluted logic and because of that during code review we failed identifying it as a potential problem. Let's treat this as a band-aid for now and as a followup think about refactoring this piece.

Test Plan:

I haven't really tested the versioned link generation, so please make sure to verify it

[TMisiukiewicz]

👍

[szymonrybczak]

FYI I checked if links generation works correctly. It works same as before. ✅

[kelset]

can confirm that the fix work, managed to test locally to generate the diff patch for upgrade-helper and by locally using this fix everything worked 👍

react-native-community/rn-diff-purge@6ba5199

let's merge this one, cp into 11.x and create a new CLI release :) no rush though, atm we're aiming at doing 0.72.1 early next week