[compositing] Point current-work symlink to compositing-2 (#13431)

Without this exception, the default algorithm picks compositing-1
("Refining") over compositing-2 ("Exploring"). This matches the
original fxtf-drafts infrastructure, which had compositing-2 as
the current work.

Author: sideshowbarker

bin/build-index.py

@@ -123,6 +123,7 @@ def create_symlink(shortname, spec_folder):
 
 
 CURRENT_WORK_EXCEPTIONS = {
+    "compositing": 2,
     "css-conditional": 5,
     "css-easing": 2,
     "css-grid": 2,