Bump FluentAssertions in /ImperatorToCK3.UnitTests

Bumps [FluentAssertions](https://github.com/fluentassertions/fluentassertions) from 8.0.0-alpha.1 to 8.0.0-rc.2.
- [Release notes](https://github.com/fluentassertions/fluentassertions/releases)
- [Changelog](https://github.com/fluentassertions/fluentassertions/blob/release-8.0/AcceptApiChanges.ps1)
- [Commits](fluentassertions/fluentassertions@8.0.0-alpha.1...8.0.0-rc.2)

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

Signed-off-by: dependabot[bot] <[email protected]>

ImperatorToCK3.UnitTests/ImperatorToCK3.UnitTests.csproj

@@ -16,7 +16,7 @@
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
-    <PackageReference Include="FluentAssertions" Version="8.0.0-alpha.1" />
+    <PackageReference Include="FluentAssertions" Version="8.0.0-rc.2" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.12.0" />
     <PackageReference Include="xunit" Version="2.9.2" />
     <PackageReference Include="xunit.runner.visualstudio" Version="3.0.0">