Publish coverage with GitHub Pages

[kvz]

Why

The previous public coverage publishing flow pushed generated files from transloadit/node-sdk into transloadit/node-sdk-coverage with a deploy key. That cross-repo write credential is unnecessary now that GitHub Pages supports Actions-based deployments from the same repository. This supersedes the signing workaround in #427 by removing the generated git push entirely.

What changed

• Replaces the node-sdk-coverage checkout/push steps with same-repo GitHub Pages deployment.
• Uploads the generated static-build directory as a normal artifact from the E2E job.
• Adds a separate Publish coverage Pages job with only contents: read, pages: write, and id-token: write.
• Removes all COVERAGE_REPO_* workflow secret references.

Operational notes

• transloadit/node-sdk Pages has been configured with build_type: workflow.
• New Pages URL: https://transloadit.github.io/node-sdk/.
• Tracking issue: Migrate public coverage publishing away from cross-repo pushes #428.

Validation

• git diff --check
• YAML parse check via Ruby
• yarn lint:changesets
• yarn lint:publish

After merge

• Run/verify the workflow on main.
• Remove the now-obsolete coverage publish secrets.
• Remove the old transloadit/node-sdk-coverage repository.