deps(test): update dependency fluentassertions to 8.7.1 (#961)

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<hr>

This PR contains the following updates:

| Package | Change | Age | Confidence |
|---|---|---|---|
|
[FluentAssertions](https://xceed.com/products/unit-testing/fluent-assertions/)
([source](https://redirect.github.com/fluentassertions/fluentassertions))
| `8.7.0` -> `8.7.1` |
[![age](https://developer.mend.io/api/mc/badges/age/nuget/FluentAssertions/8.7.1?slim=true)](https://docs.renovatebot.com/merge-confidence/)
|
[![confidence](https://developer.mend.io/api/mc/badges/confidence/nuget/FluentAssertions/8.7.0/8.7.1?slim=true)](https://docs.renovatebot.com/merge-confidence/)
|

---

### Release Notes

<details>
<summary>fluentassertions/fluentassertions (FluentAssertions)</summary>

###
[`v8.7.1`](https://redirect.github.com/fluentassertions/fluentassertions/releases/tag/8.7.1)

[Compare
Source](https://redirect.github.com/fluentassertions/fluentassertions/compare/8.7.0...8.7.1)

<!-- Release notes generated using configuration in .github/release.yml
at hotfix/8.7.1 -->

#### What's Changed

##### Others

- JSON assertions did not properly handle floats, doubles and unsigned …
by [@&#8203;dennisdoomen](https://redirect.github.com/dennisdoomen) in
[#&#8203;3105](https://redirect.github.com/fluentassertions/fluentassertions/pull/3105)
- Fixed ambiguity when using Should on a JsonNode derived class ... by
[@&#8203;JSkimming](https://redirect.github.com/JSkimming) in
[#&#8203;3102](https://redirect.github.com/fluentassertions/fluentassertions/pull/3102)

**Full Changelog**:
<fluentassertions/fluentassertions@8.7.0...8.7.1>

</details>

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test/Directory.Build.props

@@ -9,7 +9,7 @@
     </PropertyGroup>
 
     <ItemGroup>
-        <PackageReference Include="FluentAssertions" Version="8.7.0" />
+        <PackageReference Include="FluentAssertions" Version="8.7.1" />
         <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.0.0" />
         <PackageReference Include="xunit" Version="2.9.3" />
         <PackageReference Include="xunit.runner.visualstudio" Version="3.1.5">