deps: update dependency importlib-metadata to v4.12.0 (#217)

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This PR contains the following updates:

| Package | Change | Age | Adoption | Passing | Confidence |
|---|---|---|---|---|---|
| [importlib-metadata](https://github.com/python/importlib_metadata) | `==4.8.3` -> `==4.12.0` | [![age](https://badges.renovateapi.com/packages/pypi/importlib-metadata/4.12.0/age-slim)](https://docs.renovatebot.com/merge-confidence/) | [![adoption](https://badges.renovateapi.com/packages/pypi/importlib-metadata/4.12.0/adoption-slim)](https://docs.renovatebot.com/merge-confidence/) | [![passing](https://badges.renovateapi.com/packages/pypi/importlib-metadata/4.12.0/compatibility-slim/4.8.3)](https://docs.renovatebot.com/merge-confidence/) | [![confidence](https://badges.renovateapi.com/packages/pypi/importlib-metadata/4.12.0/confidence-slim/4.8.3)](https://docs.renovatebot.com/merge-confidence/) |

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