Failed to install dependency for Yjs

### Summary

There seems to be going something wrong with imports

### What platform(s) does this occur on?

Android, iOS, Web

### SDK Version

43,44,45

### Reproducible demo or steps to reproduce from a blank project

1. Import yjs 13 or 13.1 or 13.5 (12 works)
2. Wait for error:

```
package.json (3:5) Failed to resolve dependency 'yjs@13' (export 'Observable' (imported as 'Observable') was not found in 'lib0/observable' (module has no exports)
export 'floor' (imported as 'math') was not found in 'lib0/math' (module has no exports)
export 'max' (imported as 'math') was not found in 'lib0/math' (module has no exports)
export 'appendTo' (imported as 'array') was not found in 'lib0/array' (module has no exports)
export 'setIfUndefined' (imported as 'map') was not found in 'lib0/map' (module has no exports)
```

Demo: https://snack.expo.dev/aCRRsgAk-

Start with the linked Snack demo and package.json, then reproduce the Yjs 13, 13.1, and 13.5 dependency-resolution errors shown for the lib0 exports. Done means those versions install without the reported Observable, math, array, and map export failures on Android, iOS, and Web, while the existing Yjs 12 behavior remains intact.

Written by the indexing model from the issue text.