Have consistent compile lines between BUILD_TESTS enabled or not (rap…

…idsai#1401)

This will remove 1h from our conda CI builds since we can now re-use the cached object files between `libraft` and `libraft-tests`

Authors:
  - Robert Maynard (https://github.com/robertmaynard)

Approvers:
  - Vyas Ramasubramani (https://github.com/vyasr)
  - Ben Frederickson (https://github.com/benfred)
  - Divye Gala (https://github.com/divyegala)

URL: rapidsai#1401

cpp/CMakeLists.txt

@@ -70,11 +70,13 @@ option(RAFT_COMPILE_LIBRARY "Enable building raft shared library instantiations"
        ${RAFT_COMPILE_LIBRARY_DEFAULT}
 )
 
-# Needed because GoogleBenchmark changes the state of FindThreads.cmake, causing subsequent runs to
-# have different values for the `Threads::Threads` target. Setting this flag ensures
+
+# Needed because GoogleBenchmark changes the state of FindThreads.cmake, causing subsequent runs
+# to have different values for the `Threads::Threads` target. Setting this flag ensures
 # `Threads::Threads` is the same value across all builds so that cache hits occur
 set(THREADS_PREFER_PTHREAD_FLAG ON)
 
+
 include(CMakeDependentOption)
 # cmake_dependent_option( RAFT_USE_FAISS_STATIC "Build and statically link the FAISS library for
 # nearest neighbors search on GPU" ON RAFT_COMPILE_LIBRARY OFF )