x/website: use the meetup graphql API to source events

[jamalc]

The meetup API is responding with a 404 for the /pro/go/es_groups_summary endpoint. This is causing the daily website deploy job to fail.

[gopherbot]

Change https://go.dev/cl/426836 mentions this issue: cmd/golangorg: skip event step in cloudbuild deploy

[gopherbot]

Change https://go.dev/cl/429577 mentions this issue: _content,cmd: remove events section from homepage and get started page