Bump FluentAssertions from 6.7.0 to 6.8.0 (#299)

Bumps [FluentAssertions](https://github.com/fluentassertions/fluentassertions) from 6.7.0 to 6.8.0.
- [Release notes](https://github.com/fluentassertions/fluentassertions/releases)
- [Changelog](https://github.com/fluentassertions/fluentassertions/blob/develop/AcceptApiChanges.ps1)
- [Commits](fluentassertions/fluentassertions@6.7.0...6.8.0)

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

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>

Author: dependabot[bot]

src/common.props

@@ -20,7 +20,7 @@ Migrated onto .NET 6.</PackageReleaseNotes>
   <PropertyGroup>
     <XunitVersion>2.4.2</XunitVersion>
     <MicrosoftSdkVersion>17.3.2</MicrosoftSdkVersion>
-    <FluentAssertionsVersion>6.7.0</FluentAssertionsVersion>
+    <FluentAssertionsVersion>6.8.0</FluentAssertionsVersion>
     <NetCoreVersion>net6.0</NetCoreVersion>
     <NetStandardVersion>netstandard1.6</NetStandardVersion>
     <NetFrameworkLibVersion>net461</NetFrameworkLibVersion>