Fix sticky filters not working on vulnerability report

Changelog: fixed
MR: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/77647
EE: true

ee/app/assets/stylesheets/components/vulnerability_list.scss

@@ -2,7 +2,9 @@ $security-filter-height: 90px;
 $selection-summary-height: 66px;
 $selection-summary-with-error-height: 118px;
 
-@mixin sticky-top-positioning($extra: 0) {
+// Values used with calc must have units, so we need $extra to default to "0px" instead of "0"
+// stylelint-disable-next-line length-zero-no-unit
+@mixin sticky-top-positioning($extra: 0px) {
   top: calc(#{$header-height} + #{$extra});
 
   .with-performance-bar & {