Add F1 test for scoped (#64094)

Author: CyrusNajmabadi

src/VisualStudio/CSharp/Test/F1Help/F1HelpTests.cs

@@ -1994,6 +1994,17 @@ public class C
             """, "required");
     }
 
+    [Fact]
+    public async Task TestScoped()
+    {
+        await Test_KeywordAsync("""
+            sc[||]oped var r = new R();
+            ref struct R
+            {
+            }
+            """, "scoped");
+    }
+
     [Fact]
     public async Task TestDefaultConstraint()
     {