GITHUB_TOKEN is not necessary about setup-crystal-action

[MeilCli]

@oprypin
Thanks issue.
Can use the API without a token as you say, but in some cases, will get caught in rate limit?
I include the code because I do not know how rate limit is treated in github action.

[oprypin]

Fair point. Well, maybe instead you can make it implicit, so users don't need to write it out in their config.
Like here

inputs:
  token:
    default: ${{ github.token }}

[MeilCli]

@oprypin
Thanks good idea!

https://github.com/MeilCli/setup-crystal-action/releases/tag/v3.0.0
I just published v3.0.0, this version include your idea.