Fix the runtime versioner and update tool deps (#3503)

This issue was caused by a runtime crate referencing another runtime
crate with a version dependency instead of a path dependency. I've added
an error message that tells us how to fix this if it comes up again:

```txt
crate `aws-smithy-mocks-experimental` depends on crate `aws-smithy-types` crate by version instead of by path. Please update it to use path dependencies for all runtime crates.
```

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