Only use github.token on github.com

[ChristopherHX]

Description:
This expression ${{ github.server_url == 'https://github.com' && github.token || '' }} evaluates to '' if called from GHES hosted elsewhere
You can still provide your token on both github.com and GHES
See docu https://docs.github.com/en/actions/learn-github-actions/contexts.

Related issue:
Needs PullRequest: #427
#229, without the need for a new input or breaking using the token input on GHES.

Check list:

• Mark if documentation changes are required.
• Mark if tests were added or updated to cover the changes.

[brcrista]

Thanks for the suggestion! Let me try testing this against a GHES instance with #437 re-enabled.

[brcrista]

Tested on a GHES instance (3.6.0) with this workflow:

name: CI

on: [workflow_dispatch]

jobs:
  sample_build:
    runs-on: [ self-hosted ]
    steps:
      - name: "rate limit"
        run: |
          curl \
            -H "Accept: application/vnd.github.v3+json" \
            -H "Authorization: token $TOKEN" \
            https://api.github.com/rate_limit
        env:
          TOKEN: ${{ secrets.GH_DOTCOM_TOKEN }}

      - name: Clear the tool cache
        run: rm -rf /Users/runner/hostedtoolcache/Python/

      - name: Set up Python
        uses: brcrista/setup-python@patch-1
        with:
          token: ${{ secrets.GH_DOTCOM_TOKEN }}
          python-version: 3.9.12

      - name: "rate limit"
        run: |
          curl \
            -H "Accept: application/vnd.github.v3+json" \
            -H "Authorization: token $TOKEN" \
            https://api.github.com/rate_limit
        env:
          TOKEN: ${{ secrets.GH_DOTCOM_TOKEN }}

Confirmed that:

1. The token is used when it is passed to setup-python
2. Commented out the token so the input is using a default value => download succeeds

[brcrista]

Also regression-tested the default case on github.com and made sure the download still works.

[brcrista]

CI is passing now; must have been an issue with one of the hosted images.

Thanks @ChristopherHX for your contribution!