test: Enable skipped colorize test

[islandryu]

const canColorize = process.stderr?.isTTY && (
  typeof process.stderr?.getColorDepth === 'function' ?
    process.stderr?.getColorDepth() > 2 : true);

When executed with "make test", canColorize in "test-runner-output.mjs" always seems to be false.
This causes a discrepancy when running the test directly.