EditableText should not update textinput style when the textinput is …

[chunhtai]

…not attached

Description

EditableText didupdatewidget will attempt to update textinput style if the widget.style has changed.
The pr makes sure it only updates it when textinput is attached, otherwise does nothing.

Related Issues

Closes #40755

Tests

I added the following tests:
"can update style of previous activated EditableText"

Checklist

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• All existing and new tests are passing.
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Breaking Change

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[Piinks]

LGTM

[mdebbar]

LGTM. Thanks for improving this!

[miguelpruivo]

@chunhtai didn't you forget to remove the assert from here?