I feel like this is bad manners. The runners are a shared resource and you risk getting their IPs blacklisted by the sites you're scraping. I think a strict reading of the GitHub Actions TOS may prohibit this sort of usage, too.
> ... for example, don't use Actions as a content delivery network or as part of a serverless application ...
> Actions should not be used for: ... any other activity unrelated to the production, testing, deployment, or publication of the software project associated with the repository where GitHub Actions are used.
> You may only access and use GitHub Actions to develop and test your application(s).
There is a repo on GH that basically does this and can be used as a currency conversion API (with historical rates). It scrapes all values once a day with actions, commits it, and you can then query it with a cdn.
This is free(!) to host, and the commit log gives an enormous amount of detail about how the scraped resource changed over time.
I wrote more about this trick here: https://simonwillison.net/2020/Oct/9/git-scraping/
Here are 267 repos that are using it: https://github.com/topics/git-scraping?o=desc&s=updated