Rendering model is broken with regard to updates

[pjanx]

Checklist

• I have searched the issue tracker for open issues that relate to the same problem, before opening a new one.
• This issue only relates to a single bug. I will open new issues for any other problems.

Describe the bug

See the screencaps.

How to reproduce

Make some compute-expensive changes within Fyne while updating different widgets.

Screenshots

Peek.2024-11-13.10-54.webm

Screen.Recording.2024-11-13.at.10.50.39.mov

Example code

Adjust the string repeat counts to make it appropriately slow.

package main

import (
	"strings"
	"time"

	"fyne.io/fyne/v2"
	"fyne.io/fyne/v2/app"
	"fyne.io/fyne/v2/container"
	"fyne.io/fyne/v2/widget"
)

func main() {
	a := app.New()
	w := a.NewWindow("Bugs")
	w.Resize(fyne.NewSize(480, 360))
	me := widget.NewMultiLineEntry()
	l := widget.NewLabel("")
	w.SetContent(container.NewBorder(nil, nil, l, nil, me))

	long := strings.Repeat("Lorem ipsum dolor sit amet\n", 260)
	short := strings.Repeat("Lorem ipsum dolor sit amet\n", 240)
	var which bool
	t := time.NewTicker(time.Second / 2)
	go func() {
		for {
			<-t.C
			which = !which
			if which {
				me.SetText(long)
				l.SetText(":DDDDDDDDD")
			} else {
				me.SetText(short)
				l.SetText(":D")
			}
			me.TypedKey(&fyne.KeyEvent{Name: fyne.KeyPageDown})
		}
	}()
	w.ShowAndRun()
}

Fyne version

2.5.2

Go compiler version

1.23.2

Operating system and version

Linux, macOS

Additional Information

No response