RSRP-466209: Build: Sealing/unsealing a class is not detected as a public change

1. Create a regular class:

public class Foo { } 

2. In a dependent assembly, add an inheriting class:

public class Bar : Foo { } 

3. Build
4. Make Foo sealed:

public sealed class Foo { } 

5. Build again

Expected: dependent projects will be rebuilt and building the project with Bar will fail
Actual: No dependent projects are rebuilt

Also happens when unsealing a class.