Bump apollo-server from 3.9.0 to 3.12.1 in /apollo-gateway

Bumps [apollo-server](https://github.com/apollographql/apollo-server/tree/HEAD/packages/apollo-server) from 3.9.0 to 3.12.1.
- [Release notes](https://github.com/apollographql/apollo-server/releases)
- [Commits](https://github.com/apollographql/apollo-server/commits/apollo-server@3.12.1/packages/apollo-server)

---
updated-dependencies:
- dependency-name: apollo-server
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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