Pages: turn off build for non main branches

There is no option to turn off non-production builds or at least configure them, today I got a bazillion of pull requests created from Dependabot, and as you can imagine blow up the queue in Cloudflare builds

So we can choose the main branch for production builds, but there is no way to configure or turn off builds for non-production branches

BTW: also there is a bug, whenever I cancel running or queued build Cloudflare should mark Github run id with the corresponding status, otherwise pull requests are stuck with waiting status from Cloudflare forever, see conclusion property here: Checks - GitHub Docs

PS: unfortunately there is no pages category, so adding it to feedback

I believe that is in development.

Usually gets put in the Worker category.