Why `@rules_cuda//cuda:runtime` flag rather than respecting `--dynamic_mode`

[Bazel already has a flag](https://bazel.build/reference/command-line-reference#flag--dynamic_mode) (`--dynamic_mode`) to allow controlling of static vs dynamic linking. I think it's feasible to apply this to the cuda runtime. Why not use this flag? It's surprising that there's a separate flag and that the bazel flag is not respected.

If you're OK with switching to use the built-in `--dynamic_mode` I'd be happy to open a PR to implement the change.
Thanks!

Start with Bazel's --dynamic_mode reference and the @rules_cuda//cuda:runtime flag mentioned in the issue. Compare how each controls CUDA runtime linking and determine the scope of switching between them. Done means the CUDA runtime respects --dynamic_mode without requiring a separate flag, with behavior covered by the repository's relevant checks.

Written by the indexing model from the issue text.