Run dart pub global run mono_repo generate (#295)

To fix CI errors such as in #293 

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- [x] I’ve reviewed the contributor guide and applied the relevant
portions to this PR.

<details>
  <summary>Contribution guidelines:</summary><br>

- See our [contributor
guide](https://github.com/dart-lang/.github/blob/main/CONTRIBUTING.md)
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please allow for some latency before initial review feedback.
</details>

Author: mosuem