Move logic for team page filtering to API

[dirkcuys]

Currently in the deploy step,

• data is fetched
• then processed
• in the processing script, teams with dedicated sites are filtered out
• Redirects for these pages are set in s3_website_config.json during this step

Logic for filtering teams would be better placed as part of the API

[dirkcuys]

On the /teams page, they are filtered using the data in _data/teams.json: https://github.com/p2pu/p2pu-website/blob/master/en/teams/index.html#L326