Svg without viewBox does not match theme

[mondy]

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

I tried to add a new icon.
However, the theme was not reflected.
I asked a question in the fyne channel on slack.
As a conclusion, I found that the theme is not reflected if there is no viewBox attribute in the svg tag.
Would it be possible to apply the theme to svg files that do not have a viewBox attribute?

How to reproduce

Execute the following code.

Screenshots

Example code

package main

import (
	"fyne.io/fyne/v2"
	"fyne.io/fyne/v2/app"
	"fyne.io/fyne/v2/container"
	"fyne.io/fyne/v2/theme"
	"fyne.io/fyne/v2/widget"
)

func main() {
	ok := `<svg xmlns="http://www.w3.org/2000/svg" width="32" height="32" viewBox="0, 0, 32, 32"><circle cx="16" cy="16" r="14" /></svg>`
	ng := `<svg xmlns="http://www.w3.org/2000/svg" width="32" height="32"><circle cx="16" cy="16" r="14" /></svg>`

	app := app.New()
	win := app.NewWindow("")
	win.SetContent(container.NewGridWrap(
		fyne.NewSize(200, 200),
		widget.NewIcon(theme.NewThemedResource(fyne.NewStaticResource("ok_themed.svg", []byte(ok)))),
		widget.NewIcon(theme.NewThemedResource(fyne.NewStaticResource("ng_themed.svg", []byte(ng)))),
		widget.NewIcon(fyne.NewStaticResource("ok_unthemed.svg", []byte(ok))),
		widget.NewIcon(fyne.NewStaticResource("ng_unthemed.svg", []byte(ng))),
	))
	win.ShowAndRun()
}

Fyne version

v2.3.1

Go compiler version

go version go1.20.2 windows/amd64

Operating system and version

Windows10

Additional Information

No response

[andydotxyz]

Fixed for v2.3.2 :)