Update dependency FluentAssertions to v6.9.0

Author: renovate[bot]

dotnet/CucumberExpressions.Tests/CucumberExpressions.Tests.csproj

@@ -9,7 +9,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="FluentAssertions" Version="6.8.0" />
+    <PackageReference Include="FluentAssertions" Version="6.9.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.4.1" />
     <PackageReference Include="xunit" Version="2.4.2" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.4.5">