workaround for stage 3

Author: zwarich

src/Init/Data/Vector/Extract.lean

@@ -9,6 +9,8 @@ prelude
 import Init.Data.Vector.Lemmas
 import Init.Data.Array.Extract
 
+set_option maxHeartbeats 20000000
+
 /-!
 # Lemmas about `Vector.extract`
 -/