Fix CI

Dependencies

• [2] TEQJC3HX Add 03-nix-container

Change contents

• edit in 03-nix-container/demo-inside-nix-develop.sh at line 2
  [2.5759]

  [2.5759]
  + # shellcheck disable=SC2288
• replacement in 03-nix-container/demo-inside-nix-develop.sh at line 15
  [2.6155]→[2.6155:6191](∅→∅)
  − x docker load -i ./result-container
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  [2.6191]
  + x docker load -i "${dir}/result-container"