`<pre>`: Disable auto-hiding scrollbar in legacy Edge

Created by: MartijnCuppens

Disable auto-hiding scrollbar in legacy Edge to avoid overlap, making it impossible to interact with the content.

Ref. https://github.com/twbs/bootstrap/commit/f3fc973dd93d1bb69183404d9985157284a3be7f#diff-7f9eec82312835f6155c8de839bf0e49