When an element with "display:flex; flex-direction:row" is selected, selection.toString() inserts newlines between the child elements.

Bug is on both Desktop and iOS Safari

Safari Version: Version 17.0 (18616.1.27.111.22, 18616)

Bug is not present in Chrome

Repro steps:

```
myDiv.innerHTML = `<div style="display:flex; flex-direction:row;"><div>a</div><div>b</div></div>`;
r = document.createRange();
r.setStartBefore(myDiv);
r.setEndAfter(myDiv);
sel = window.getSelection();
sel.removeAllRanges();
sel.addRange(r);
sel.toString()
```

Expected: "ab"

Actual: "
a
b
"