Remove Issue regarding StaticRange validity

Author: dandclark

css-highlight-api-1/Overview.bs

@@ -514,16 +514,6 @@ Range Updating and Invalidation</h3>
 	are greater than the corresponding node’s <a spec=dom>length</a>,
 	The user agent must behave as if it was equal to that <a spec=dom>length</a>.
 
-	Issue(4597): As far as I am aware,
-	prior uses of {{StaticRange}}s were for [=ranges=] created by the user agent
-	and passed to the author.
-	Here, it's the other way around,
-	which raises (for the first time?)
-	the question of invalidation of static ranges.
-	Can the above work?
-	Is it Fast enough that it's worth distinguishing static and live ranges?
-	Would some alternative handling be better?
-
 	Issue(4598): The interaction of {{StaticRange}}s in a [=custom highlight=]
 	and [[css-contain-2]]
 	seems problematic: