Move to clang-format 18

[bernhardmgruber]

Our CCCL pre-commit informed us of an available update that includes moving from clang-format 17.0.6 to 18.1.8. @jrhemstad pointed out this needs to be synced with the version installed in the devcontainers, so developers will have a good experience of getting the same formatting locally as what the CI checks for. Hence this issue.

I kindly ask to upgrade the clang-format version to the latest 18 release in devcontainers. We can then fix the pre-commit clang-format version to that version.

[trxcllnt]

You can bump the CCCL clang format version by updating this line in the image matrix.

[bernhardmgruber]

Thx a lot! PR is here: #343