Update dependency mypy to v1.4.0 (#239)

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This PR contains the following updates:

| Package | Change | Age | Adoption | Passing | Confidence |
|---|---|---|---|---|---|
| [mypy](https://www.mypy-lang.org/)
([source](https://github.com/python/mypy),
[changelog](https://mypy-lang.blogspot.com/)) | `==1.3.0` -> `==1.4.0` |
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|
[![adoption](https://badges.renovateapi.com/packages/pypi/mypy/1.4.0/adoption-slim)](https://docs.renovatebot.com/merge-confidence/)
|
[![passing](https://badges.renovateapi.com/packages/pypi/mypy/1.4.0/compatibility-slim/1.3.0)](https://docs.renovatebot.com/merge-confidence/)
|
[![confidence](https://badges.renovateapi.com/packages/pypi/mypy/1.4.0/confidence-slim/1.3.0)](https://docs.renovatebot.com/merge-confidence/)
|

---

### Release Notes

<details>
<summary>python/mypy</summary>

### [`v1.4.0`](https://github.com/python/mypy/compare/v1.3.0...v1.4.0)

[Compare
Source](https://github.com/python/mypy/compare/v1.3.0...v1.4.0)

</details>

---

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requirements.txt

@@ -3,7 +3,7 @@ aiofiles==23.1.0
 black==23.3.0
 coverage==7.2.7
 GitPython==3.1.31
-mypy==1.3.0
+mypy==1.4.0
 nest_asyncio==1.5.6
 networkx==3.1
 pdoc==14.0.0