Wrong return type in Renderer::ensureMarkupIsSafe()

Checked this with phpstorm and it's also flagging this function as an incorrect return.

Looking at the code $elements['#markup'] is being updated and $elements returned so clearly an array.

Not sure we can add the return type without a CR at the very least. I think the docs update is fine, but there are at least a handful of contrib modules extending the Renderer class that would break if the override ::ensureMarkupIsSafe.

I have removed the return type, but as the function is protected, i think it was ok to leave it there (i did query the function within git and i did not find a match except for his function itself)

Committed and pushed e65cc2e481 to 11.x and 02428eb872 to 10.3.x and 983d2909eb to 10.2.x. Thanks!

Backported to 10.2.x as a docs fix.

Automatically closed - issue fixed for 2 weeks with no activity.