breaking change of Woodpecker CI on their next branch

Link to Woodpecker CI next changelog: https://woodpecker-ci.org/docs/next/migrations#next-200

See #2335. I still don't know what caused the linkcheck errors though. Not sure how it works. But that PR works fine for my project based on this CI result https://ci.codeberg.org/repos/12769/pipeline/31/4 since I got a built page https://uncomfyhalomacro.codeberg.page/Rudolf.jl/dev/