Authenticate dashboard GitHub API requests

[danielporterda]

Summary

• Adds GitHub API authorization headers to the version-dashboard generator when GH_TOKEN or GITHUB_TOKEN is present.

Stack

This is PR 3/8 in the generated-reference automation split.

Base: generated-reference-02-wallet-openrpc-nav-products
Head: generated-reference-03-dashboard-github-token

Validation

• python3 -m pytest tests/test_generate_network_component_versions.py tests/test_wallet_kernel_nav.py tests/test_docs_env.py; python3 -m py_compile scripts/generate_network_component_versions.py scripts/generate_wallet_gateway_openrpc_reference.py scripts/docs_env.py; git diff --check