Bump FluentAssertions from 5.10.3 to 8.0.1 (#517)

Bumps [FluentAssertions](https://github.com/fluentassertions/fluentassertions) from 5.10.3 to 8.0.1.
- [Release notes](https://github.com/fluentassertions/fluentassertions/releases)
- [Changelog](https://github.com/fluentassertions/fluentassertions/blob/main/AcceptApiChanges.ps1)
- [Commits](fluentassertions/fluentassertions@5.10.3...8.0.1)

---
updated-dependencies:
- dependency-name: FluentAssertions
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

tests/Directory.Build.props

@@ -31,7 +31,7 @@
 
   <ItemGroup>
     <PackageReference Include="AutoFixture" Version="4.18.1" />
-    <PackageReference Include="FluentAssertions" Version="5.10.3" />
+    <PackageReference Include="FluentAssertions" Version="8.0.1" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.11.1" />
     <PackageReference Include="Moq" Version="4.20.72" />
     <PackageReference Include="MSTest.TestAdapter" Version="3.6.0" />