DEV: Fix `hljs.highlightBlock` deprecation (#14908)

DEV: Fix hljs.highlightBlock deprecation (#14908)

diff --git a/app/assets/javascripts/discourse/app/lib/highlight-syntax.js b/app/assets/javascripts/discourse/app/lib/highlight-syntax.js
index 62e2a05..74bf28f 100644
--- a/app/assets/javascripts/discourse/app/lib/highlight-syntax.js
+++ b/app/assets/javascripts/discourse/app/lib/highlight-syntax.js
@@ -41,7 +41,7 @@ export default function highlightSyntax(elem, siteSettings, session) {
       }
 
       e.classList.remove("lang-auto");
-      hljs.highlightBlock(e);
+      hljs.highlightElement(e);
     });
   });
 }

GitHub sha: 7ea2bf52cc3ac96b63cb69ce80a94d83b8061b10

This commit appears in #14908 which was approved by eviltrout. It was merged by CvX.