Roll engine to 1348ab5b63adc18148f161876a4b1cacd5ec0779 (#15645)

Includes:
* Roll Dart to f1ebe2bd5cfcb6b522e5b4fd406cdabb1a2d2091. (#4805)
diff --git a/bin/internal/engine.version b/bin/internal/engine.version
index 3934c7c..4052075 100644
--- a/bin/internal/engine.version
+++ b/bin/internal/engine.version
@@ -1 +1 @@
-464af48eb202ac7c6c43e2af64aadec9a72d9bb6
+1348ab5b63adc18148f161876a4b1cacd5ec0779