Update dependency pymdown-extensions to v10.3.1 (#153)

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This PR contains the following updates:

| Package | Change | Age | Adoption | Passing | Confidence |
|---|---|---|---|---|---|
|
[pymdown-extensions](https://togithub.com/facelessuser/pymdown-extensions)
| `==10.3` -> `==10.3.1` |
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|
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|
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|

---

### Release Notes

<details>
<summary>facelessuser/pymdown-extensions (pymdown-extensions)</summary>

###
[`v10.3.1`](https://togithub.com/facelessuser/pymdown-extensions/releases/tag/10.3.1)

[Compare
Source](https://togithub.com/facelessuser/pymdown-extensions/compare/10.3...10.3.1)

#### 10.3.1

- **FIX**: SuperFences: Fix an issue where braces were not handled
properly in attributes.

</details>

---

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docs/requirements.txt

@@ -3,4 +3,4 @@ mkdocs-material
 mkdocstrings[python]==0.23.0
 mkdocs-include-markdown-plugin
 pygments
-pymdown-extensions==10.3
+pymdown-extensions==10.3.1