bugfix: false positive on expressions containing Count

Author: Meir017

src/FluentAssertions.Analyzers.Tests/Tips/CollectionTests.cs

@@ -329,6 +329,7 @@ public class CollectionTests
         [AssertionDiagnostic(@"var array = new string[1, 1]; array.Length.Should().Be(0{0});")]
         [AssertionDiagnostic(@"var array = new string[2, 2]; array.Length.Should().Be(0{0});")]
         [AssertionDiagnostic(@"var array = new string[3, 3, 3]; array.Length.Should().Be(0{0});")]
+        [AssertionDiagnostic(@"int[] array1 = [1, 2, 3]; int[] array2 = [4, 5, 6]; var both = x.Concat(y).ToArray(); (array1.Length + array2.Length).Should().Be(both.Length{0});")]
         [Implemented(Reason = "https://github.com/fluentassertions/fluentassertions.analyzers/issues/309")]
         public void CollectionShouldHaveCount_LengthShouldBe_TestNoAnalyzer(string assertion) => DiagnosticVerifier.VerifyCSharpDiagnosticUsingAllAnalyzers(new StringBuilder()
             .AppendLine("using System;")