Persist benchmark results in CI

[ryanslade]

Benchmark results are now collected to a json file which will be appended to a file in s3.

Another action will generate static HTML from these results and push them to GitHub Pages.

[exekias]

will this be enough to order results? wondering what will be the way to put this in a graph later

[ryanslade]

We have a timestamp in the data too which we can use for ordering.

[andrew-farries]

• Should the benchmark workflow have a workflow_dispatch event so that it can be run manually as well as on merge?
• The benchmark-results.json file in S3 is currently empty even though this workflow looks like it's been run a few times. Is that expected?

[ryanslade]

• Should the benchmark workflow have a workflow_dispatch event so that it can be run manually as well as on merge?

Will do

• The benchmark-results.json file in S3 is currently empty even though this workflow looks like it's been run a few times. Is that expected?

Yep, that's fine. I've been throwing away the test runs on the PR since they'll have an incorrect SHA.