docs(gha): Update setup-python version in GitHub Actions.md

[luis-giraldo]

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

Description

We need to update the following action because not doing so will result on an error on certain architectures, see error below.

`Run actions/setup-python@v1
  with:
    python-version: 3.8
    architecture: x64
Error: Version 3.8 with arch x64 not found
Available versions: `

Version 4 of this action fixed the issue for me.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my feature, policy, or fix is effective and works
• New and existing tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[gruebel]

hey @luis-giraldo thanks for the contribution, but your change doesn't fit with what you wrote.

[luis-giraldo]

hey @gruebel thanks for the feedback, already fixed it on my last commit

[gruebel]

hey @luis-giraldo can you recreate your PR and create the merge against the main branch? You falsely set it to master. Changing it breaks the PR content.

[luis-giraldo]

@gruebel sure, I'll close this PR and I'll open a new one. I'll also mention you on the new one