Bump cachix/install-nix-action from v8 to v10 (#791)

Dependencies

• [2] LX326CB7 Add hydra OpenAPI description (#750)
• [3] NKPSTN6H add github ci tests
• [4] 27T5ZSQE Only run the 'build' test

Change contents

• replacement in .github/workflows/test.yml at line 12
  [3.206]→[3.206:247](∅→∅)
  − - uses: cachix/install-nix-action@v8
  [3.206]

  [3.247]
  + - uses: cachix/install-nix-action@v10
• replacement in .github/workflows/test.yml at line 21
  [2.124]→[2.124:165](∅→∅)
  − - uses: cachix/install-nix-action@v8
  [2.124]

  [2.165]
  + - uses: cachix/install-nix-action@v10