Update dependency FluentAssertions to 8.1.0

Author: renovate[bot]

src/UnitTests/UnitTests.csproj

@@ -21,7 +21,7 @@
     <ProjectReference Include="..\CodeGeneration\CodeGeneration.csproj" />
   </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="FluentAssertions" Version="8.0.1" />
+    <PackageReference Include="FluentAssertions" Version="8.1.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.13.0" />
     <PackageReference Include="xunit" Version="2.9.3" />
     <PackageReference Include="xunit.runner.visualstudio" Version="3.0.2" />