4.0.2

Merge branch 'Instagram:main' into master

New Package Release

SPM number10 (#1487)

Summary:
## Changes in this pull request

 A better version of https://github.com/Instagram/IGListKit/issues/1465 =)

- SPM support with script-based generations.

- added macOS Catalyst support

 ### Generate SPM layout

1. From **project's root** run:

   `bash scripts/generate_spm_sources_layout.sh`

  2. Commit Changes

 Repeat those steps each time you delete/add the project's files. **Make sure** to have this CI step which will check that `generate_spm_sources_layout.sh` is not broken.

Issue fixed: https://github.com/Instagram/IGListKit/issues/1368 #1406

### Checklist

- [ ] All tests pass. Demo project builds and runs.
- [ ] I added tests, an experiment, or detailed why my change isn't tested.
- [ ] I added an entry to the `CHANGELOG.md` for any breaking changes, enhancements, or bug fixes.
- [ ] I have reviewed the [contributing guide](https://github.com/Instagram/IGListKit/blob/master/.github/CONTRIBUTING.md)

Pull Request resolved: https://github.com/Instagram/IGListKit/pull/1487

Reviewed By: DimaVartanian, candance

Differential Revision: D30428297

Pulled By: lorixx

fbshipit-source-id: 655291ff03445dec9b0b8cd97916f0c88207e9a7