Merge branch 'fix-confirm-button-in-darkmode' into 'master'

Fix .btn-confirm blend mode in dark mode

See merge request gitlab-org/gitlab!70814

app/assets/stylesheets/themes/_dark.scss

@@ -202,7 +202,8 @@ body.gl-dark {
     &.btn-info,
     &.btn-success,
     &.btn-danger,
-    &.btn-warning {
+    &.btn-warning,
+    &.btn-confirm {
       &-tertiary {
         mix-blend-mode: screen;
       }