fix(common): remove ZkvmIO

[zobront]

Is your feature request related to a problem? Please describe.
To allow for compilation of kona-common in SP1, it is required to stop NativeIO from compiling. The current workaround is to implement a ZkvmIO alternative which is triggered when target_os = "zkvm", which contains only no-ops.

@clabby would like to make sure this workaround is removed, so adding this ticket to ensure that gets done.

Describe the solution you'd like
TBD

Describe alternatives you've considered
The obvious answer seems to be to use feature flags. I had a WIP version that used a default io feature flag, which could be turned off when importing into a zkvm environment. However, because kona is set up as a workspace, it was difficult to get the io feature to turn off across the board without adding a feature to many of the crates with lots of messy interdependencies.

Additional context
N/A