Layout step fails on Windows with error "Failed to find a parent section match for a page"

[Atomk]

Zig's website builds fail on Windows with error "Failed to find a parent section match for a page" because some path separators are hardcoded to /, and cached paths are saved with the native separator resulting in failing equality checks with paths using the / separator.

md_rel_path = 'news/welcome-jacob-young.smd'
section_path = 'C:\...\www.ziglang.org\.zig-cache\zine\s\en-US\news\s'
section file contents:
    news\migrate-to-self-hosting\index.smd
    news\carmen-the-allocgator\index.smd
    news\welcome-matthew-lugg.smd
    news\first-donor-bounty.smd
    news\announcing-donor-bounties.smd
    news\2024-financials.smd
    news\bounties-damage-open-source-projects.smd
    news\welcome-jacob-young.smd
    news\0.11.0-postponed-again.smd
    news\goodbye-cpp\index.smd
    news\financials-update.smd
    news\jakub-konka-hired-full-time\index.smd
    news\website-i18n-redesign.smd
    news\zig-0.7.1.smd
    news\fosdem-2021.smd
    news\statement-regarding-zen-programming-language.smd
    news\announcing-zig-software-foundation.smd

Notice how the path separator in md_rel_path differs from the ones in the section file contents. Hacking around I was able to confirm that fixing this issue allows to complete a ziglang.org build on Windows.