A Docker container action declares an input named package_name. Its entrypoint expects the value as the first positional argument. Which metadata is needed in addition to the input declaration?

1. Map ${{ inputs.package_name }} into runs.args.
2. Put the expression in the Dockerfile CMD and expect the GitHub expression engine to expand it during the image build.
3. Set runs.main to inputs.package_name.
4. Put the input under outputs so GitHub passes it as the first argument.