Roll external/abseil_cpp/ 8b81b77c5..af5128235 (36 commits)

abseil/abseil-cpp@8b81b77...af51282

Created with:
  roll-dep external/abseil_cpp

Author: GitHub Actions[bot]

DEPS

@@ -3,7 +3,7 @@ use_relative_paths = True
 vars = {
   'github': 'https://github.com',
 
-  'abseil_revision': '8b81b77c5e4251de400909e15279653f49b0a6ec',
+  'abseil_revision': 'af5128235231b9f9b3ea1368b7d88b6d55560eca',
 
   'effcee_revision': '874b47102c57a8979c0f154cf8e0eab53c0a0502',