Cannot call workflow_dispatch with optional boolean input with no default value from API

[r7kamura]

I have a workflow that responds to workflow_dispatch events like this:

name: foo
on:
  workflow_dispatch:
    inputs:
      foo:
        description: Example optional boolean input without `default` property.
        required: false
        type: boolean

This worked fine for running it from the actions page of the repository. I wanted the checkbox to appear on the web UI, so I provided boolean input. This worked perfectly well.

But when I tried to run it from the GitHub API, it failed with the following error:

$ GH_DEBUG=api gh workflow run foo
> POST /repos/r7kamura/sandbox/actions/workflows/████████/dispatches HTTP/1.1
> Host: api.github.com
> Accept: application/vnd.github.merge-info-preview+json, application/vnd.github.nebula-preview
> Authorization: token ████████████████████
> Content-Type: application/json; charset=utf-8
> Time-Zone: Asia/Tokyo
> User-Agent: GitHub CLI 2.14.2

{
    "inputs": {},
    "ref": "main"
}

...

< HTTP/2.0 422 Unprocessable Entity
< Access-Control-Allow-Origin: *
...

{
    "message": "Provided value '' for input 'foo' not in the list of allowed values",
    "documentation_url": "https://docs.github.com/rest/reference/actions#create-a-workflow-dispatch-event"
}
* Request took 318.624ms
could not create workflow dispatch event: HTTP 422: Provided value '' for input 'foo' not in the list of allowed values (https://api.github.com/repos/r7kamura/sandbox/actions/workflows/████████/dispatches)

As a workaround, I changed the workflow file like this, and it worked.

 name: foo
 on:
   workflow_dispatch:
     inputs:
       foo:
+        default: "false"
         description: Example optional boolean input without `default` property.
         required: false
         type: boolean

I'd like this to be handled well on the GitHub API side without having to specify a default String value, what do you think?