Detect wildcard requirements before publishing

When publishing arti 1.4.2, I had a problem halfway through the release because of a wildcard dependency in tor-rtcompat. See !2910 (merged)

We should have a maint script for detecting unsupported dependency requirements in our lib crates (currently just * wildcards, AFAICT), and ideally run it in CI (basically disallowing * requirements for all our lib crates).