hydra: Change the `tarball' job to use `--with-nix'.

Dependencies

• [2] QK2OXCKP hydra/release.nix: move manual to tarball build, restore version in store path for tarball build
• [*] T4LLYESZ * Nix expression for building Hydra.

Change contents

• edit in release.nix at line 24
  [2.125]

  [2.125]
  +

  + configureFlags = "--with-nix=${nix}";