Maintenance: remove GH pages for docs

[sthulb]

Summary

We no longer use GH pages for hosting the docs, we should remove the code from GitHub Actions.

Why is this needed?

We now host docs on docs.powertools.aws.dev instead of GitHub Pages

Which area does this relate to?

No response

Solution

No response

Acknowledgment

• This request meets Powertools for AWS Lambda (.NET) Tenets