Pin FluentAssertions to version 7.0.0 (#2028)

Directory.Packages.props

@@ -8,7 +8,7 @@
     <PackageVersion Include="Acornima.Extras" Version="1.1.1" />
     <PackageVersion Include="BenchmarkDotNet" Version="0.14.0" />
     <PackageVersion Include="BenchmarkDotNet.TestAdapter" Version="0.13.12" />
-    <PackageVersion Include="FluentAssertions" Version="8.0.0" />
+    <PackageVersion Include="FluentAssertions" Version="[7.0.0]" />
     <PackageVersion Include="Flurl.Http.Signed" Version="4.0.2" />
     <PackageVersion Include="Jurassic" Version="3.2.8" />
     <PackageVersion Include="Meziantou.Analyzer" Version="2.0.186" />