fix: stop duplicate generated release notes

[web3dev1337]

Summary

• make the Windows tag workflow the only workflow that generates GitHub release notes
• keep the macOS tag workflow limited to uploading macOS assets to the existing release
• remove the now-unused macOS release version step

Test Plan

• ruby -e "require 'yaml'; YAML.load_file('.github/workflows/macos.yml'); YAML.load_file('.github/workflows/windows.yml'); puts 'workflow yaml ok'"
• node --check server/index.js