Fixup for https://phabricator.services.mozilla.com/D308885

Signed-off-by: Oriol Brufau <obrufau@igalia.com>

Author: Loirooriol

stylo_static_prefs/preferences.toml

@@ -37,6 +37,7 @@
 "layout.css.stylo-local-work-queue.in-worker" = 0
 "layout.css.stylo-work-unit-size" = 16
 "layout.css.system-ui.enabled" = true
+"layout.css.text-decoration-inset-percentage.enabled" = false
 "layout.css.tree-counting-functions.enabled" = false
 "layout.css.webkit-fill-available.all-size-properties.enabled" = true
 "layout.css.webkit-fill-available.enabled" = true