Re-enable bench-summary in CI

[TomAFrench]

Benchmark summaries were disabled in 67485f1 so we no longer get benchmarks commented on PRs.

This was done as we were getting this error after Charlie's migration of docker images.

Context from Palla.

RE awscli it's possible you can just remove the apt install awscli from the Earthfiles, since they should all be using Charlie's base image which apparently includes it (see here). You should also ensure the base image on all the scripts that were installing awscli is switched to Charlie's, or install the awscli via curl.