build: Remove obsolete Docker Compose version keys

[Copilot]

Docker Compose now treats the top-level version field as obsolete, causing warnings on routine commands. This change removes deprecated declarations from the compose files used by default and dev workflows.

• Scope

  • Removed top-level version from:
    • docker-compose.yml
    • docker/dev.yml

• Result

  • Eliminates Compose warnings about obsolete version attributes while keeping service definitions unchanged.

• Example of the change

  # before
  version: "3.9"
  services:
    taxonomy_api:
      ...
  
  # after
  services:
    taxonomy_api:
      ...