How to define sequence/list inputs for custom github actions?

Question

I have a custom GitHub action defined via Node.js that I'd like to be able to pass input to as a sequence. I.e.:

...
uses: ./path/to/action
with:
  a: some value
  b:
    - some value 1
    - some value 2

I.e. I would like to receive an array of values in the JavaScript code. Is this possible? I'm using the @actions/core library. Below is my action definition:

name: ...
description: ...
inputs:
  a:
    description: ...
    required: false
    default: ''
  b:  # <= I'd like this to be a sequence
    description: 'List of commands to execute'
    required: true
    default:
      - thing1
      - thing2
outputs:
  time:
    description: ...
runs:
  using: 'node16'
  main: 'index.js'