build(deps): bump FluentAssertions from 5.10.3 to 6.1.0

Bumps [FluentAssertions](https://github.com/fluentassertions/fluentassertions) from 5.10.3 to 6.1.0.
- [Release notes](https://github.com/fluentassertions/fluentassertions/releases)
- [Changelog](https://github.com/fluentassertions/fluentassertions/blob/master/AcceptApiChanges.ps1)
- [Commits](fluentassertions/fluentassertions@5.10.3...6.1.0)

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

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

Author: dependabot[bot]

src/ReactiveMarbles.CacheDatabase.Tests/ReactiveMarbles.CacheDatabase.Tests.csproj

@@ -19,7 +19,7 @@
     </PackageReference>
     <PackageReference Include="DiffEngine" Version="7.1.0" />
     <PackageReference Include="PublicApiGenerator" Version="10.2.0" />
-    <PackageReference Include="FluentAssertions" Version="5.10.3" />
+    <PackageReference Include="FluentAssertions" Version="6.1.0" />
     <PackageReference Include="Microsoft.Reactive.Testing" Version="5.0.0" />
     <PackageReference Include="ReactiveUI.Testing" Version="14.3.1" />
   </ItemGroup>