fix: tolerance of test in ci

Author: algebraic-dev

tests/lean/libuv_timer.lean

@@ -16,7 +16,7 @@ def assertDuration (should : Nat) (eps : Nat) (x : IO α) : IO α := do
   return res
 
 -- generous tolerance for slow CI systems
-def EPS : Nat := 7
+def EPS : Nat := 4
 
 def await (x : Task α) : IO α := pure x.get