HTML: Remove UA styles for h1 in article, aside, nav, section

See whatwg/html#11102

Author: zcorpan

Diff for: html/rendering/non-replaced-elements/sections-and-headings/headings-styles-no-h1-in-section.tentative.html

@@ -19,12 +19,6 @@
 h5 { margin-block: 1.67em; font-size: 0.83em; font-weight: bold; }
 h6 { margin-block: 2.33em; font-size: 0.67em; font-weight: bold; }
 
-:is(article, aside, nav, section) h1 { margin-block: 0.83em; font-size: 1.50em; }
-:is(article, aside, nav, section) :is(article, aside, nav, section) h1 { margin-block: 1.00em; font-size: 1.17em; }
-:is(article, aside, nav, section) :is(article, aside, nav, section) :is(article, aside, nav, section) h1 { margin-block: 1.33em; font-size: 1.00em; }
-:is(article, aside, nav, section) :is(article, aside, nav, section) :is(article, aside, nav, section) :is(article, aside, nav, section) h1 { margin-block: 1.67em; font-size: 0.83em; }
-:is(article, aside, nav, section) :is(article, aside, nav, section) :is(article, aside, nav, section) :is(article, aside, nav, section) :is(article, aside, nav, section) h1 { margin-block: 2.33em; font-size: 0.67em; }
-
 </style>
 
 <div id="log"></div>