Remove the dependency on `tokio` for most tests

None of the tests, besides `eipw-lint/tests/eipv.rs`, really need tokio to run. Maybe depend on a lighter weight async runtime, or just fail if the future isn't immediately resolved.

Start by inspecting the test setup and dependency declarations, with eipw-lint/tests/eipv.rs as the exception to preserve. Determine how the other tests invoke tokio and whether a lighter runtime or immediate-future handling fits; done means those tests no longer depend on tokio while eipv.rs still runs successfully.

Written by the indexing model from the issue text.