[INFRA]: Prepare GitHub CI for HostJIT transition

### Is this a duplicate?

- [x] I confirmed there appear to be no [duplicate issues](https://github.com/NVIDIA/cccl/issues) for this request and that I agree to the [Code of Conduct](CODE_OF_CONDUCT.md)

### Overview

We should improve CI to better isolate development and user environments. When running v2 tests, CI env shouldn't have any compilers, libraries, or executables installed in user env other than what's declared as `cuda.compute` dependency. We should also re-think what CTK test matrix for v2.

This issue can be closed by
- setting up CI jobs that test cuda.computev2 in minimal Linux/Windows Docker containers (e.g., python:-slim) for testing to ensure zero system dependencies
- Re-evaluate CTK matrix testing coverage to ensure that we are testing across important 12.x and 13.x environments. At minimum, we should test against oldest/newest 12.x and oldest/newest 13.x.

### Details

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