DOCS: update news and authors for v1.7

[Sergei-Lebedev]

What

Update NEWS and AUTHORS for UCC v1.7

[greptile-apps]

Greptile Summary

Updated documentation for UCC v1.7 release by adding comprehensive release notes to NEWS and two new contributors to AUTHORS.

• Added 50+ changes to NEWS covering NVLS multinode support, memory type fixes, ncclAlltoAll support, extensive CI improvements, and perftest enhancements
• Added Arnaud Celermajer and Daniel Pressler to AUTHORS (note: git shows Arnaud's name as "Celermajer (Nvidia)")
• All PRs referenced in NEWS (TL/CUDA: Multinode NVLS #1185-TL/UCP: fix inplace for allgather, alltoall #1254) exist in git history and match the described changes
• Release notes are well-organized by category (Core, TL/CUDA, TL/UCP, TL/NCCL, Build/Test, Documentation, Tools)

Confidence Score: 4/5

• Safe to merge with one minor correction needed for author name format
• Documentation updates are accurate and comprehensive, with all referenced PRs verified in git history. Only issue is author name format inconsistency.
• AUTHORS file needs minor correction to match git commit author name

Important Files Changed

Filename	Overview
AUTHORS	Added two contributors (Arnaud Celermajer and Daniel Pressler) in alphabetical order, though Arnaud's git commit shows name as "Celermajer (Nvidia)"
NEWS	Added comprehensive v1.7 release notes documenting 50+ changes across Core, TL/CUDA, TL/UCP, TL/NCCL, Build/Test, Documentation, and Tools

[greptile-apps]

_{2 files reviewed, 1 comment}

_{Edit Code Review Agent Settings | Greptile}

[dpressle]

/build

[janjust]

@wfaderhold21 please approve so we can branch