Bump FluentAssertions from 6.12.0 to 6.12.1 (#129)

Bumps [FluentAssertions](https://github.com/fluentassertions/fluentassertions) from 6.12.0 to 6.12.1.
- [Release notes](https://github.com/fluentassertions/fluentassertions/releases)
- [Changelog](https://github.com/fluentassertions/fluentassertions/blob/develop/AcceptApiChanges.ps1)
- [Commits](fluentassertions/fluentassertions@6.12.0...6.12.1)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Simon McKenna <[email protected]>

Author: dependabot[bot]

Directory.Packages.props

@@ -10,7 +10,7 @@
     </PackageVersion>
     <PackageVersion Include="FluentAssertions" Version="6.12.1" />
     <PackageVersion Include="FsUnit.xUnit" Version="6.0.1" />
-    <PackageVersion Include="FSharp.Core" Version="8.0.100" />
+    <PackageVersion Include="FSharp.Core" Version="8.0.400" />
     <PackageVersion Include="lolcat" Version="1.1.64" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.11.1" />
     <PackageVersion Include="Nerdbank.GitVersioning" Version="3.6.143">