[TASK] Remove radio buttons from "new content elements" overview

Remove radio buttons from "new content elements" as icons
serves the same purpose
Change-Id: Ibea517d19389ad2645d630b4416e7f45207faec7
Fixes: #38623
Releases: 6.1
Reviewed-on: https://review.typo3.org/12566
Reviewed-by: Oliver Hader
Tested-by: Oliver Hader
Reviewed-by: Georg Ringer
Tested-by: Georg Ringer