update slide_puzzle to latest commit (flutter#993)

johnpryan · web-flow · commit ff405c894c3e · 2022-01-18T17:41:31.000-08:00
diff --git a/web/slide_puzzle b/web/slide_puzzle
@@ -1 +1 @@
-Subproject commit e2afb1403b7ac59bc9959a8ab4211d6e782005c0
+Subproject commit b0e2ea71941c098df65d015f5b3a8cf72e7da076
