[FEA]: Change devcontainer.json to not require a GPU

[jrhemstad]

Is this a duplicate?

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Area

Infrastructure

Is your feature request related to a problem? Please describe.

As a CCCL developer, I'd like to be able to use the DevContainers without necessarily needing a GPU because I could be interested in just compiling the tests and not actually running them.

However, CCCL's devcontainer.json currently lists a GPU as a host requirement:

cccl/.devcontainer/devcontainer.json

Lines 4 to 6 in 6a2185a

	"hostRequirements": {
	"gpu": true
	},

Describe the solution you'd like

We should instead list a GPU as optional:

  "hostRequirements": {
    "gpu": "optional"
  },

Describe alternatives you've considered

No response

Additional context

No response