If you are trying to reproduce Unity APIUpdater issues it should be enough to include only the source code and assemblies used in your project. So, to reduce the project size, you can:
- Make a backup of your project
- Delete all non script assets (i.e, only keep source code, assemblies, asmdef and their related .meta files)
- Reopen the project (the issue should still happen)
- Report the issue normally (using the bug reporter)