Bump the all group with 1 update

Bumps FluentAssertions from 8.8.0 to 8.9.0

---
updated-dependencies:
- dependency-name: FluentAssertions
  dependency-version: 8.9.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: all
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

src/tests/Together.IntegrationTests/Together.IntegrationTests.csproj

@@ -12,7 +12,7 @@
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.3.0" />
     <PackageReference Include="MSTest.TestAdapter" Version="4.1.0" />
     <PackageReference Include="MSTest.TestFramework" Version="4.1.0" />
-    <PackageReference Include="FluentAssertions" Version="8.8.0" />
+    <PackageReference Include="FluentAssertions" Version="8.9.0" />
   </ItemGroup>
 
   <ItemGroup Label="GlobalUsings">