Bug: Deletion of leading new lines in block not possible

Describe a bug: Currently in version 2.26.5 it is not possible to delete leading new lines (`
`) which can be inserted with shift+enter. Looks like this is the same issue as #726, which should already be fixed.

Steps to reproduce:
1. Try to delete the `
` in editorjs.
```
{
"time": 1678038907409,
"blocks": [
{
"id": "990n123EDf",
"data": {
"text": "A heading",
"level": 2
},
"type": "header"
},
{
"id": "jxsCeHKOhB",
"data": {
"text": "
You can't delete the newline above this..."
},
"type": "paragraph"
}
],
"version": "2.26.5"
}
```

Device, Browser, OS: Tested in Chrome and Edge.

Editor.js version: 2.26.5