Fix Faiss Warning in CI

[tarang-jain]

Not sure if we can get rid of the RESCAN, but it seems that faiss_gpu_objs is an OBJECT library.
Link to warning related to this: https://github.com/rapidsai/cuvs/actions/runs/20800604992/job/59744590582?pr=1664

[tarang-jain]

Looks like this does not work, and requires the RESCAN.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Enterprise

Run ID: 4dcd3f74-7bfc-4d07-b244-aecf9e8de879

📥 Commits

Reviewing files that changed from the base of the PR and between 3da8994 and 704c283.

📒 Files selected for processing (1)

• cpp/cmake/thirdparty/get_faiss.cmake

---

📝 Walkthrough

Summary by CodeRabbit

• Chores
  • Optimized GPU and static library build configuration for improved linking behavior.

Walkthrough

The change modifies CMake's FAISS target composition when GPU support and static library builds are enabled. Instead of applying LINK_GROUP:RESCAN to both GPU objects and the final CPU target together, it now directly injects GPU objects and applies LINK_GROUP:RESCAN only to the final FAISS CPU target.

Changes

Cohort / File(s)	Summary
FAISS CMake Linking cpp/cmake/thirdparty/get_faiss.cmake	Restructured static target composition for GPU+static builds: GPU objects now directly injected with LINK_GROUP:RESCAN applied only to final CPU FAISS target instead of both together.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title 'Fix Faiss Warning in CI' is related to the changeset, which modifies faiss target composition to address a CI warning.
Description check	✅ Passed	The description is related to the changeset, explaining the investigation into a Faiss CI warning and noting that faiss_gpu_objs is an OBJECT library.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

_{Review rate limit: 9/10 reviews remaining, refill in 6 minutes.}

_{Comment @coderabbitai help to get the list of available commands and usage tips.}