The failover runbook's Windows switch scope returns to the native Windows jobs:
remove the Python runtime eligibility sentences, the pool Python prerequisite,
and the proposal links. The #3629 self-hosted Python runtime proposal is
retired (deleted as obsolete after its unmeasured-throughput run), and a new
implemented note records that the Windows x64 runtime lane stays on
GitHub-hosted Windows with the evidence and alternatives. Bilingual sidecars
re-recorded.
Tianyi Cui