Upgrade Hugo to 0.125.2

[chalin]

Site diff:

$ (cd userguide/public && git diff -bw --ignore-blank-lines -I '<meta |^\s$|^"\s*/>$|^">$') | grep ^diff | grep -v _print
diff --git a/blog/2023/priorities-for-2024/index.html b/blog/2023/priorities-for-2024/index.html
diff --git a/blog/2024/0.9.0/index.html b/blog/2024/0.9.0/index.html
diff --git a/docs/index.html b/docs/index.html