Avoid sudden scroll jumps on swapping standings rows

Modern browsers try to "follow" elements jumping out of the viewport.
Set overflow-anchor: none to disable the behavior.

c.f.
https://developer.mozilla.org/en-US/docs/Web/CSS/overflow-anchor

Author: nya3jp

frontend/css/livesite.css

@@ -65,6 +65,7 @@ a.no-decoration {
 
 .standard-standings {
   line-height: 1.3;
+  overflow-anchor: none;
 }
 
 .standard-standings .team-row {

frontend/src/components/common/AnimatingTable.tsx

@@ -23,8 +23,6 @@ type AnimatingTableProps = {
 type AnimatingTableSnapshot = {
   lastKeyOrder: string[];
   lastKeyToOffsetTop: Map<string, number>;
-  // TODO - this is a workaround to fix scrolling position sometimes moves.
-  scrollPos: number;
 };
 
 export default class AnimatingTable extends React.Component<
@@ -46,8 +44,7 @@ export default class AnimatingTable extends React.Component<
       lastKeyOrder.push(row.dataset.key!);
       lastKeyToOffsetTop.set(row.dataset.key!, row.offsetTop);
     }
-    const scrollPos = document.documentElement.scrollTop;
-    return { lastKeyOrder, lastKeyToOffsetTop, scrollPos };
+    return { lastKeyOrder, lastKeyToOffsetTop };
   }
 
   componentDidUpdate(
@@ -56,7 +53,7 @@ export default class AnimatingTable extends React.Component<
     snapshot: AnimatingTableSnapshot
   ) {
     const { delay = 1000 } = this.props;
-    const { lastKeyOrder, lastKeyToOffsetTop, scrollPos } = snapshot;
+    const { lastKeyOrder, lastKeyToOffsetTop } = snapshot;
     const rows = Array.from(this.ref.current!.children) as HTMLElement[];
 
     // Check if the order changed.
@@ -73,11 +70,6 @@ export default class AnimatingTable extends React.Component<
       }
     }
 
-    // TODO - this is a workaround to fix scrolling position sometimes moves.
-    if (scrollPos) {
-      document.documentElement.scrollTop = scrollPos;
-    }
-
     // Cancel all animations.
     this.timers.clearTimeouts();
     for (const cancel of this.cancels.splice(0)) {