build(deps): bump FluentAssertions from 6.9.0 to 6.10.0 in /src

Bumps [FluentAssertions](https://github.com/fluentassertions/fluentassertions) from 6.9.0 to 6.10.0.
- [Release notes](https://github.com/fluentassertions/fluentassertions/releases)
- [Changelog](https://github.com/fluentassertions/fluentassertions/blob/develop/AcceptApiChanges.ps1)
- [Commits](fluentassertions/fluentassertions@6.9.0...6.10.0)

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

Signed-off-by: dependabot[bot] <support@github.com>

src/Directory.build.props

@@ -50,7 +50,7 @@
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.5.0" />
     <PackageReference Include="xunit" Version="2.4.2" />
     <PackageReference Include="Xunit.StaFact" Version="1.1.11" />
-    <PackageReference Include="FluentAssertions" Version="6.9.0" />
+    <PackageReference Include="FluentAssertions" Version="6.10.0" />
     <PackageReference Include="Microsoft.Reactive.Testing" Version="5.0.0" />
     <PackageReference Include="PublicApiGenerator" Version="10.3.0" />
     <PackageReference Include="Verify.Xunit" Version="19.10.0" />