Remove caching FIXMEs

Code here has been in production a week now, so we no longer need to support
the old HTML structure.

Change-Id: I508dec3294588c9fc7f86958c47a3e5b52493df9

resources/common/typography.less

@@ -70,8 +70,6 @@ pre,
 	}
 }
 
-// FIXME: [ id='bodyContent' ] selector needed for cached HTML.
-[ id='bodyContent' ],
 .vector-body {
 	font-size: @font-size-base;
 	// Support IE 9-11, Trident cuts values 2 digits after decimal point.

resources/skins.vector.styles.legacy/layouts/screen.less

@@ -58,19 +58,11 @@ body {
 	z-index: @z-index-indicators;
 }
 
-// FIXME: [ id='bodyContent' ] selector needed for cached HTML.
-[ id='bodyContent' ],
 .vector-body {
 	position: relative;
 	z-index: @z-index-base;
 }
 
-// FIXME: Temporarily disable the core rule which applies to the wrong element.
-// The definition in core still needs work (see T279008).
-.mw-parser-output:after {
-	content: none;
-}
-
 /* Head */
 #mw-page-base {
 	.vertical-gradient( @background-color-base, @background-color-secondary, 50%, 100% );

resources/skins.vector.styles/components/UserLinks.less

@@ -35,10 +35,6 @@
 
 		.vector-menu-content-list {
 			li {
-				// FIXME: the following font-size rule is for cached HTML. It can be removed when
-				// I068c5233bb25a7b141e66a6726b5761841f83eb2 is in production.
-				// stylelint-disable-next-line declaration-no-important
-				font-size: 100% !important;
 				width: 100%;
 				margin: 0;