Add note about upgrading to FF 109 and link to corresponding issue

Author: JakeChampion

.github/workflows/main.yml

@@ -215,6 +215,8 @@ jobs:
         path: "/home/runner/.cargo/bin/viceroy"
         key: crate-cache-viceroy-${{ env.viceroy_version }}
 
+    # https://github.com/fastly/js-compute-runtime/issues/361
+    # TODO: Use engine-debug on all apps once we upgrade to FF 109
     - name: Download Engine
       uses: actions/download-artifact@v3
       with: