Make warpspeed scan tunable

[bernhardmgruber]

• Duplicate exclusive/sum benchmark for warpspeed since it is too different from the old implementation
• Hardcode benchmark OffsetT to uint64
• Review warpspeed scan tuning parameters and expose the relevant ones

This PR will create a conflict with #7565 and I am fine with merging this PR after it. This PR is needed to unblock @gonidelis tuning the new scan implementation.

Fixes: #7893
Fixes: #7894

[bernhardmgruber]

With the changes in this PR, I can start a tuning run for the warpspeed scan:

cccl/build_tune$ CUDA_VISIBLE_DEVICES=0 ../benchmarks/scripts/search.py -R 'cub.bench.scan.exclusive.sum.warspeed' -a 'KeyT{ct}=I32' -a 'Elements{io}[pow2]=28'
 ctk:  13.2.51
cccl:  v3.4.0.dev-208-g2f040ac1d4
cub.bench.scan.exclusive.sum.warspeed.wrps_5.lbi_8.ipt_224 0.3516259758697389
cub.bench.scan.exclusive.sum.warspeed.wrps_3.lbi_3.ipt_48 0.9829544835206165
cub.bench.scan.exclusive.sum.warspeed.wrps_7.lbi_7.ipt_64 1.005813892002792
cub.bench.scan.exclusive.sum.warspeed.wrps_2.lbi_1.ipt_144 0.9774011267682982
cub.bench.scan.exclusive.sum.warspeed.wrps_4.lbi_2.ipt_64 0.9943421016735846
cub.bench.scan.exclusive.sum.warspeed.wrps_6.lbi_4.ipt_24 0.988571386808916
cub.bench.scan.exclusive.sum.warspeed.wrps_1.lbi_4.ipt_48 0.5148809219190508
cub.bench.scan.exclusive.sum.warspeed.wrps_5.lbi_7.ipt_216 0.3626834049278357
cub.bench.scan.exclusive.sum.warspeed.wrps_3.lbi_2.ipt_216 0.7330993445471629
cub.bench.scan.exclusive.sum.warspeed.wrps_5.lbi_5.ipt_152 0.7456895936547066
cub.bench.scan.exclusive.sum.warspeed.wrps_1.lbi_4.ipt_128 0.8565018316886749
cub.bench.scan.exclusive.sum.warspeed.wrps_3.lbi_7.ipt_24 0.7393161554878765
cub.bench.scan.exclusive.sum.warspeed.wrps_3.lbi_2.ipt_128 1.0000902018895734

[github-actions]

🥳 CI Workflow Results

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See results here.