CodeLens does not invalidate for changes in downstream projects

Version Used: e9fd4dc7

Steps to Reproduce:

1. Create project A:

   public static class First {
     public static void Method() { }
   }
   

2. Create project B, which references project A:

   public class Second {
     public void Method() {
       First.Method();
     }
   }
   

3. Observe the CodeLens reference count on First.Method

4. Comment out Second.Method

5. Observe the CodeLens reference count on First.Method

Expected Behavior:

• At step (3), the reference count is 1
• At step (5), the reference count is 0

Actual Behavior:

• ✔ At step (3), the reference count is 1
• ❌ At step (5), the reference count is 1

Additional Details:

The change in step (4) does not update the project version which is used here for data point invalidation:

https://github.com/dotnet/roslyn/blob/6eecbdbeff1a547709b53f5bdc93b60749c6b1ef/src/VisualStudio/Core/Def/Implementation/CodeLens/CodeLensCallbackListener.cs#L70