AssetsLibrary is a fairly old library for accessing the users' photo. It has long been deprecated. You already know that. Apple introduced the Photos framework as a replacement.

Since Xcode 26 requires iOS 15 as the minimum supported deployment target, and the AssetsLibrary framework was deprecated long ago, it’s no longer available or recommended to use in newer versions of iOS and Xcode.

Quote Apple Staff, Quinn “The Eskimo" , he confirmed this is a bug:

This is obviously a bug and I encourage you to file a report about it. Please post your bug number, just for the record.

If your code does not implicitly import this AssetsLibrary. Then we have to check:

1. If it is imported/linked by 3rd party dependencies
2. If you mistakenly linked the AssetsLibrary(maybe in General -> Frameworks, Libraries, and Embedded Content)

You can list the podfile.lock or Package.resolved so that we can have a further analysis.