fix: replace :first-child with :first-of-type in mapbox-gl.css (fixes #13639)#13646

ragini-pandey wants to merge 1 commit intomapbox:mainmapbox/mapbox-gl-js:mainfrom

ragini-pandey:fix/css-first-child-ssr-warningragini-pandey/mapbox-gl-js:fix/css-first-child-ssr-warningCopy head branch name to clipboard