feat: use github token by default

[nikaro]

Set ${{ github.token }} as the default value for github_token input.
This is the common practice, examples:

• https://github.com/actions/checkout/blob/main/action.yml#L24
• 🚸 use GitHub token by default astral-sh/setup-uv#61

[woile]

Hi, if you use the github token, other actions are not triggered. Do you know if this has been solved?

See the warning:
https://commitizen-tools.github.io/commitizen/tutorials/github_actions/#automatic-bumping-of-version

[nikaro]

Hi, if you use the github token, other actions are not triggered. Do you know if this has been solved?

See the warning: https://commitizen-tools.github.io/commitizen/tutorials/github_actions/#automatic-bumping-of-version

Yes i know, this is intended to work this way so i do not think it will be "solved".

But at least it allows to push the tags without having to explicitly pass the default token (making it a little less verbose), which is enough if we do not want to trigger a workflow on tag, at least my use cases do not need it. And for those who need it, it is documented in your link (i did not touched this part of the README).