[css-contain-2] Remove "at risk" marker from style containment

Author: frivoal

css-contain-2/Overview.bs

@@ -17,7 +17,6 @@ Editor: Vladimir Levin, Google, vmpstr@google.com, w3cid 75295
 Abstract: This CSS module describes the 'contain' property, which indicates that the element's subtree is independent of the rest of the page. This enables heavy optimizations by user agents when used well.
 Test Suite: https://test.csswg.org/harness/results/css-contain-1_dev/
 WPT Path Prefix: css/css-contain/
-At risk: [=style containment=] and the ''contain: style'' value
 </pre>
 <pre class="anchors">
 spec: css2; urlPrefix: https://www.w3.org/TR/CSS2/
@@ -327,8 +326,6 @@ Strong Containment: the 'contain' property</h2>
 				quote-scoping-004.html
 			</wpt>
 
-			Note: This value is at-risk.
-
 		<dt><dfn>paint</dfn>
 		<dd>
 			This value turns on <a>paint containment</a> for the element.
@@ -838,8 +835,6 @@ Layout Containment</h3>
 <h3 id='containment-style'>
 Style Containment</h3>
 
-	Note: Style Containment is at-risk.
-
 	Giving an element <dfn export>style containment</dfn>
 	and has the following effects: