Use ES modules for gatsby config

[zbynek]

This should unlock some dependency updates

[halkeye]

this is so cool. I wasn't aware we upgraded gatsby enough to support this.

[zbynek]

@halkeye there are still some files that we might be able to rename, but when I tried that with ucfirst I ran into some issues with Eslint. Also Eslint says p-queue is not reachable even though it clearly is. Maybe because type:module in package.json is expected by Eslint but causes problems with Gatsby? (for plugin-site; other workspaces are fine). Despite these I think this is ready for merge, we can improve it more when newer versions of Eslint and/or Gatsby are available.

[NotMyFault]

Awesome, thanks so much!

[halkeye]

do we still need this for 18? 18 should have full module support
if not, do you want to goto 20 instead? I don't really like using the flag.

[zbynek]

this is only used during lint+test stage. I think it's more related to Jest implementation than Node version, see https://jestjs.io/docs/ecmascript-modules

[halkeye]

Also Eslint says p-queue is not reachable even though it clearly is.

can you tell me how to generate that output?

[zbynek]

@halkeye see https://github.com/jenkins-infra/plugin-site/pull/1429/checks?check_run_id=14690302296 -- caused by reverting Eslint config in 618e48d
Apparently that's just a bug in Eslint import-js/eslint-plugin-import#1810

[halkeye]

I'm pretty checked out. If you think its a win, go ahead and merge it. I'm still a little uncomfortable with --experimental-vm-modules but I know how messy jest can get.