Incorrect text scroll offset after pasting into a text input

## Bevy version and features

main

## What you did

Ran:
```
cargo run --example multiple_text_inputs --features="system_clipboard"
```

Then copy and pasted the following into the first text input:
"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua."

## What went wrong

The text should fill the first input, with the view scrolled so the last line with the cursor is clamped to the bottom of the input box.