hydra-api: don't restrict input types

Dependencies

• [2] LX326CB7 Add hydra OpenAPI description (#750)
• [3] HPXFXHFS Remove SHA-1 hash from BuildProducts
• [4] P32OJ3RU Jobsets: update schema to align with the API

Change contents

• edit in hydra-api.yaml at line 691
  [2.16412]→[2.16412:16673](∅→∅)
  − enum:

  − - bzr

  − - bzr-checkout

  − - bitbucketpulls

  − - darcs

  − - git

  − - githubpulls

  − - gitlabpulls

  − - hg

  − - path

  − - svn

  − - svn-checkout