The benchmarks have been failing with a timeout. Some recent failures:

https://ci.chromium.org/ui/p/flutter/builders/prod/Mac_mokey%20microbenchmarks/3991/infra
https://ci.chromium.org/ui/p/flutter/builders/prod/Mac_mokey%20microbenchmarks/3994/infra
https://ci.chromium.org/ui/p/flutter/builders/prod/Mac_mokey%20microbenchmarks/3995/infra