Manually roll Flutter Engine from cbb9d0b06 to cef721963 (#112895)

https://github.com/flutter/engine/compare/37d8342ccac159892d93008f64c9a3ac0ed2f9e1...cef721963336c56e88127d82db6400ff1d247b26

* Revert "[Windows] Move to Visual Studio 2019" (https://github.com/flutter/engine/pull/36606)

Issue: https://github.com/flutter/flutter/issues/112894
diff --git a/bin/internal/engine.version b/bin/internal/engine.version
index 6b5ad97..92975cf 100644
--- a/bin/internal/engine.version
+++ b/bin/internal/engine.version
@@ -1 +1 @@
-cbb96d0b06d7646f7cfa793f13eec690318037ac
+cef721963336c56e88127d82db6400ff1d247b26