upgrade: update dependency dart to v3.4.4 (#525)

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This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| [dart](https://dart.dev/)
([source](https://togithub.com/dart-lang/sdk)) | patch | `3.4.3` ->
`3.4.4` |

---

### Release Notes

<details>
<summary>dart-lang/sdk (dart)</summary>

### [`v3.4.4`](https://togithub.com/dart-lang/sdk/compare/3.4.3...3.4.4)

[Compare
Source](https://togithub.com/dart-lang/sdk/compare/3.4.3...3.4.4)

</details>

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.tool-versions

@@ -1,2 +1,2 @@
-dart 3.4.3
+dart 3.4.4
 flutter 3.22.2-stable