fix: remove duplicate _ogFileSet/hasOgImage from merge

The upstream merge introduced a second hasOgImage implementation
(using a hardcoded .cache/og path) alongside our existing one
(using OG_CACHE_DIR). Removed the duplicate; kept ours.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

eleventy.config.js

@@ -441,20 +441,6 @@ export default function (eleventyConfig) {
     }
   });
 
-  // Cache: directory listing built once per build instead of 3,426 existsSync calls
-  let _ogFileSet = null;
-  eleventyConfig.on("eleventy.before", () => { _ogFileSet = null; });
-  function hasOgImage(ogSlug) {
-    if (!_ogFileSet) {
-      const ogDir = resolve(__dirname, ".cache", "og");
-      try {
-        _ogFileSet = new Set(readdirSync(ogDir));
-      } catch {
-        _ogFileSet = new Set();
-      }
-    }
-    return _ogFileSet.has(`${ogSlug}.png`);
-  }
   eleventyConfig.addTransform("og-fix", function (content, outputPath) {
     if (!outputPath || !outputPath.endsWith(".html")) return content;