[UI] Unable to remove breakpoint for empty line

### Apache NetBeans version

Apache NetBeans 17

### What happened

That is a small UI bug. Exists for PHP files and does not exists for JS files. Not sure about other languages (java, cpp, etc.)

It's much simpler to explain how to reproduce the problem and that will be also a description of the issue.

1. Write few lines of code (as I mentioned works for PHP, not sure about other file types)
2. Make sure that last line does not have a new line symbol at the end
3. Put a breakpoint on last line by clicking on line number panel
4. Delete content of the last line, but don't delete that line completely
5. Try to remove the breakpoint - you won't succeed to do that

The only way to delete breakpoint in such cases is to write in that line something and then you will be able to remove a breakpoint.

### How to reproduce

_No response_

### Did this work correctly in an earlier version?

No / Don't know

### Operating System

Windows 10

### JDK

16.0.1

### Apache NetBeans packaging

Apache NetBeans provided installer

### Anything else

_No response_

### Are you willing to submit a pull request?

No

Reproduce the issue in a PHP file using the line-number panel: place a breakpoint on the final non-newline-terminated line, empty that line without deleting it, and try to remove the breakpoint. Compare the behavior with JavaScript if useful; done means the breakpoint can be removed from the empty final line.

Written by the indexing model from the issue text.