Upgrade to `@apollo/server` v5 blocked by unmaintained `@as-integrations/koa`

`@as-integrations/koa` hasn't seen any maintenance in a long time and doesn't officially support `@apollo/server` v5. The same is the case for the other community integrations.

Can the apollographql organization help modernize the integrations to ensure users have a smooth upgrade path?

Start by reviewing the repository's integration support and the compatibility requirements for @apollo/server v5, then inspect how community integrations such as @as-integrations/koa are maintained. Done means the relevant integrations have a clear maintenance path and officially support the v5 upgrade; the issue does not name specific files or tests.

Written by the indexing model from the issue text.