Roll external/re2/ 66a656e6d..a4b2aeed3 (15 commits)

google/re2@66a656e...a4b2aee

Created with:
  roll-dep external/re2

Author: GitHub Actions[bot]

DEPS

@@ -12,7 +12,7 @@ vars = {
   # Use protobufs before they gained the dependency on abseil
   'protobuf_revision': 'v21.12',
 
-  're2_revision': '66a656e6d9f8b78806c76201eb03038e85103e28',
+  're2_revision': 'a4b2aeed3a1c1c5df854aabfccad852008add45e',
 
   'spirv_headers_revision': '97e96f9e9defeb4bba3cfbd034dec516671dd7a3',