deps: update dependency fluentassertions to 6.12.1

Author: renovate[bot]

Directory.Packages.props

@@ -12,7 +12,7 @@
     <!-- Testing -->
     <PackageVersion Include="FakeItEasy" Version="7.4.0" />
     <PackageVersion Include="FakeItEasy.Analyzer.CSharp" Version="6.1.1" />
-    <PackageVersion Include="FluentAssertions" Version="6.12.0" />
+    <PackageVersion Include="FluentAssertions" Version="6.12.1" />
     <PackageVersion Include="FsCheck.Xunit" Version="2.16.6" />
     <PackageVersion Include="FsCheck" Version="2.16.6" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.9.0" />