Revert "Update Sizzle: use documentElement in focus selector. Fixes #13378."

This reverts commit ae7efb6bc2a6e29f798e6906d217c1e7f2445c29.

diff --git a/src/sizzle b/src/sizzle
index 578e0c6f403e5819eb7cff953990229c5593e0cf..cf19fa8dd6b7fda254bb3434f63d590845eaa7bf 160000 (submodule)
--- a/src/sizzle
+++ b/src/sizzle
@@ -1 +1 @@
-Subproject commit 578e0c6f403e5819eb7cff953990229c5593e0cf
+Subproject commit cf19fa8dd6b7fda254bb3434f63d590845eaa7bf