Reported by @BrandonXLF on https://gerrit.wikimedia.org/r/c/mediawiki/extensions/SyntaxHighlight_GeSHi/ /653609/1#message-b88df1699c057bde874103460ece9321841c2bfc:
This change causes any floating elements beside the syntaxhighlight block to have unclickable portions where the syntaxhighlight block is stacked over the floating element due to the position: relative;. For example, the links in the navbox next to the syntaxhighlight block at https://www.mediawiki.org/wiki/OOUI/Widgets/Icons,_Indicators,_and_Labels are unclickable.