Revert "html2pdf: use headless=new explicitly"

This reverts commit 56bba5fa4a1d9ea4a36b8c2b7671fb4f4ee24cc7.
diff --git a/ci/html2pdf b/ci/html2pdf
index 43f9534..a6a684e 100755
--- a/ci/html2pdf
+++ b/ci/html2pdf
@@ -1,4 +1,4 @@
 #!/bin/sh -eu
 in=$1 out=$2 page0=${3:-} page1=${4:-$page0}
-google-chrome --disable-web-security --user-data-dir="./" --disable-background-networking --enable-features=NetworkService,NetworkServiceInProcess --disable-background-timer-throttling --disable-backgrounding-occluded-windows --disable-breakpad --disable-client-side-phishing-detection --disable-component-extensions-with-background-pages --disable-default-apps --disable-dev-shm-usage --disable-extensions --disable-features=TranslateUI,BlinkGenPropertyTrees,ImprovedCookieControls,SameSiteByDefaultCookies,LazyFrameLoading --disable-hang-monitor --disable-ipc-flooding-protection --disable-popup-blocking --disable-prompt-on-repost --disable-renderer-backgrounding --disable-sync --force-color-profile=srgb --metrics-recording-only --no-first-run --enable-automation --password-store=basic --use-mock-keychain --headless=new --hide-scrollbars --mute-audio --blink-settings=primaryHoverType=2,availableHoverTypes=2,primaryPointerType=4,availablePointerTypes=4 --no-sandbox --no-startup-window --disable-gpu --run-all-compositor-stages-before-draw --no-pdf-header-footer  --virtual-time-budget=42000 --print-to-pdf="$out".tmp "$in"
+google-chrome --disable-web-security --user-data-dir="./" --disable-background-networking --enable-features=NetworkService,NetworkServiceInProcess --disable-background-timer-throttling --disable-backgrounding-occluded-windows --disable-breakpad --disable-client-side-phishing-detection --disable-component-extensions-with-background-pages --disable-default-apps --disable-dev-shm-usage --disable-extensions --disable-features=TranslateUI,BlinkGenPropertyTrees,ImprovedCookieControls,SameSiteByDefaultCookies,LazyFrameLoading --disable-hang-monitor --disable-ipc-flooding-protection --disable-popup-blocking --disable-prompt-on-repost --disable-renderer-backgrounding --disable-sync --force-color-profile=srgb --metrics-recording-only --no-first-run --enable-automation --password-store=basic --use-mock-keychain --headless=old --hide-scrollbars --mute-audio --blink-settings=primaryHoverType=2,availableHoverTypes=2,primaryPointerType=4,availablePointerTypes=4 --no-sandbox --no-startup-window --disable-gpu --run-all-compositor-stages-before-draw --no-pdf-header-footer  --virtual-time-budget=42000 --print-to-pdf="$out".tmp "$in"
 pdfseparate -f 1 -l 1 "$out".tmp $out