Separate CUB's catch2 test binaries by default for CI.

[alliepiper]

No description provided.

[miscco]

That error is really strange:

  FAILED: cub/test/CMakeFiles/cub.cpp11.test.device_segmented_reduce_iterators_64bit.lid_0.dir/catch2_test_device_segmented_reduce_iterators_64bit.cu.o 
  /usr/bin/sccache /usr/local/cuda/bin/nvcc -forward-unknown-to-host-compiler -ccbin=/usr/bin/g++ -DCUB_CONFIG_MAIN -DCUB_IGNORE_DEPRECATED_CPP_DIALECT -DTEST_LAUNCH=0 -DTHRUST_DEVICE_SYSTEM=THRUST_DEVICE_SYSTEM_CUDA -DTHRUST_HOST_SYSTEM=THRUST_HOST_SYSTEM_CPP -DVAR_IDX=0 -D_CCCL_NO_SYSTEM_HEADER -I/home/coder/cccl/cub/test -I/home/coder/cccl/cub/cub/cmake/../.. -I/home/coder/cccl/libcudacxx/lib/cmake/libcudacxx/../../../include -I/home/coder/cccl/thrust/thrust/cmake/../.. -isystem /usr/local/cuda/targets/x86_64-linux/include -isystem /home/coder/cccl/build/cub-cpp11/Metal/include -isystem /home/coder/cccl/build/cub-cpp11/_deps/catch2-src/single_include -O3 -DNDEBUG -std=c++11 "--generate-code=arch=compute_60,code=[compute_60,sm_60]" "--generate-code=arch=compute_70,code=[compute_70,sm_70]" "--generate-code=arch=compute_80,code=[compute_80,sm_80]" -Xcompiler=-Werror -Xcompiler=-Wall -Xcompiler=-Wextra -Xcompiler=-Winit-self -Xcompiler=-Woverloaded-virtual -Xcompiler=-Wcast-qual -Xcompiler=-Wpointer-arith -Xcompiler=-Wvla -Xcompiler=-Wno-gnu-line-marker -Xcompiler=-Wno-gnu-zero-variadic-macro-arguments -Xcompiler=-Wno-unused-function -Wreorder -Xcudafe=--display_error_number -Xcudafe=--promote_warnings -Wno-deprecated-gpu-targets -MD -MT cub/test/CMakeFiles/cub.cpp11.test.device_segmented_reduce_iterators_64bit.lid_0.dir/catch2_test_device_segmented_reduce_iterators_64bit.cu.o -MF cub/test/CMakeFiles/cub.cpp11.test.device_segmented_reduce_iterators_64bit.lid_0.dir/catch2_test_device_segmented_reduce_iterators_64bit.cu.o.d -x cu -c /home/coder/cccl/cub/test/catch2_test_device_segmented_reduce_iterators_64bit.cu -o cub/test/CMakeFiles/cub.cpp11.test.device_segmented_reduce_iterators_64bit.lid_0.dir/catch2_test_device_segmented_reduce_iterators_64bit.cu.o
  /home/coder/cccl/cub/test/catch2_main.cuh(52): error #135: namespace "Catch" has no member "Session"
  
  /home/coder/cccl/cub/test/catch2_main.cuh(57): error #135: namespace "Catch" has no member "clara"
  
  /home/coder/cccl/cub/test/catch2_main.cuh(59): error #20: identifier "Opt" is undefined
  
  3 errors detected in the compilation of "/home/coder/cccl/cub/test/catch2_test_device_segmented_reduce_iterators_64bit.cu".

[alliepiper]

@miscco I've seen that when the catch2 header is included in a test case (usually when VSCode automatically inserts it -_-). I think we found a WAR for these issues, I'll try to get that in ASAP.

[alliepiper]

This is ready for review and should unblock folks who are stuck on CI timeouts.