Only run the 'build' test

Dependencies

• [2] NKPSTN6H add github ci tests

Change contents

• replacement in .github/workflows/test.yml at line 14
  [2.275]→[2.275:319](∅→∅)
  − - run: nix-build -A checks.x86_64-linux
  [2.275]
  + - run: nix-build -A checks.x86_64-linux.build