Revert "Make large diffs open quickly and scroll as one surface (#3212)"

This reverts commit b599d38a77.

packages/app/src/utils/diff-rendering.ts

@@ -2,28 +2,6 @@ interface HighlightLikeToken {
   text: string;
 }
 
-interface StyledHighlightToken extends HighlightLikeToken {
-  style: string | null;
-}
-
-export function compactHighlightTokens(
-  tokens: readonly StyledHighlightToken[],
-): StyledHighlightToken[] {
-  const compacted: StyledHighlightToken[] = [];
-  for (const token of tokens) {
-    if (token.text.length === 0) {
-      continue;
-    }
-    const previous = compacted.at(-1);
-    if (previous?.style === token.style) {
-      previous.text += token.text;
-      continue;
-    }
-    compacted.push({ text: token.text, style: token.style });
-  }
-  return compacted;
-}
-
 // Preserve row height when a gutter or diff cell is intentionally blank.
 // Non-breaking space because the gutter <Text> uses numberOfLines={1}, which
 // collapses a plain ASCII space to zero height on web.