add missing develop dependency

Dependencies

• [2] ZQLF4QLV Replace TestHTTPMockServer with python script
• [3] LYO7KK3J Address PR comments:
• [4] RWNXH3H2 lastModified -> lastModifiedDate
• [5] KPWMZFHZ Add runHydra shell

Change contents

• replacement in flake.nix at line 511
  [3.250]→[2.0:28](∅→∅)
  − foreman python3
  [3.250]

  [3.275]
  + foreman python3 netcat-openbsd