delete and backspace buttons after undo and redo

### Apache NetBeans version

Apache NetBeans 21

### What happened

when I press delete or backspace it creates extra characters in the start of the line, see video.

On video I press delete a few times then I make pause and then start pressing backspace for a few times

https://github.com/apache/netbeans/assets/37518271/bc9aee10-ee21-4434-8b56-d8ec9718a937

### Language / Project Type / NetBeans Component

PHP project

### How to reproduce

To get into this mode I pressed undo button a few times, then redo... It does not always bring you into this mode, but very often.

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

No / Don't know

### Operating System

Windows 10 version 10.0 running on amd64; UTF-8; en_AU (nb)

### JDK

19.0.2; Java HotSpot(TM) 64-Bit Server VM 19.0.2+7-44

### Apache NetBeans packaging

Apache NetBeans provided installer

### Anything else

_No response_

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

No

Start by reproducing the issue in Apache NetBeans 21 on Windows 10 with a PHP project: perform several undo and redo actions, then use Delete and Backspace. The fix is complete when these keys no longer insert extra characters at the start of the line after undo and redo.

Written by the indexing model from the issue text.