After Form rename cannot generate event handlers

### Environment

Visual Studio 2022 17.5.3

### .NET version

.NET 6

### Did this work in a previous version of Visual Studio and/or previous .NET release?

_No response_

### Issue description

After a Form rename cannot generate any event handlers from properties view,

### Steps to reproduce

1. Create a .NET 6 Windows Forms project
2. Rename `Form1` to `MainForm`
3. Add a button to the form
4. Double click the button or try to add a Click event handler from Properties view.

### Diagnostics

_No response_