PEP 664: Update actual 3.11.0a6 release date (#2389)

Author: hugovk

pep-0664.rst

@@ -48,10 +48,10 @@ Actual:
 - 3.11.0 alpha 3: Wednesday, 2021-12-08
 - 3.11.0 alpha 4: Monday, 2022-01-14
 - 3.11.0 alpha 5: Thursday, 2022-02-03
+- 3.11.0 alpha 6: Monday, 2022-03-07
 
 Expected:
 
-- 3.11.0 alpha 6: Monday, 2022-02-28
 - 3.11.0 alpha 7: Tuesday, 2022-04-05
 - 3.11.0 beta 1: Friday, 2022-05-06