Fix bug in device selection in jit-cdi mode

[elezar]

This change fixes a bug added in #1267. This bug caused device selection via the NVIDIA_VISIBLE_DEVICES envvar to not work as expected.

Before this change:

$ docker run --rm -ti --runtime=nvidia -e NVIDIA_VISIBLE_DEVICES=0 ubuntu nvidia-smi -L
GPU 0: NVIDIA A100-SXM4-40GB (UUID: GPU-4cf8db2d-06c0-7d70-1a51-e59b25b2c16c)
GPU 1: NVIDIA A100-SXM4-40GB (UUID: GPU-4404041a-04cf-1ccf-9e70-f139a9b1e23c)
GPU 2: NVIDIA A100-SXM4-40GB (UUID: GPU-79a2ba02-a537-ccbf-2965-8e9d90c0bd54)
GPU 3: NVIDIA A100-SXM4-40GB (UUID: GPU-662077db-fa3f-0d8f-9502-21ab0ef058a2)
GPU 4: NVIDIA A100-SXM4-40GB (UUID: GPU-ec9d53cc-125d-d4a3-9687-304df8eb4749)
GPU 5: NVIDIA A100-SXM4-40GB (UUID: GPU-3eb87630-93d5-b2b6-b8ff-9b359caf4ee2)
GPU 6: NVIDIA A100-SXM4-40GB (UUID: GPU-8216274a-c05d-def0-af18-c74647300267)
GPU 7: NVIDIA A100-SXM4-40GB (UUID: GPU-b1028956-cfa2-0990-bf4a-5da9abb51763)

With this change:

$ docker run --rm -ti --runtime=nvidia -e NVIDIA_VISIBLE_DEVICES=0 ubuntu nvidia-smi -L
GPU 0: NVIDIA A100-SXM4-40GB (UUID: GPU-4cf8db2d-06c0-7d70-1a51-e59b25b2c16c)

As a follow-up we should consider switching to a multi-GPU instance for our testing.

[elezar]

I have created #1356 to add multi-GPU tests to the CI.