Merge branch 'readmore-fix-shadow-darkmode' into 'master'

Fix Read more shadow in darkmode

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/144568



Merged-by: Scott Hampton <shampton@gitlab.com>
Approved-by: Scott Hampton <shampton@gitlab.com>
Approved-by: Julia Miocene <jmiocene@gitlab.com>
Approved-by: Ross Byrne <robyrne@gitlab.com>
Co-authored-by: Sascha Eggenberger <seggenberger@gitlab.com>

app/assets/stylesheets/framework/read_more.scss

@@ -33,9 +33,5 @@
     top: calc(var(--read-more-height, #{$fallback}) - #{$scrim} - #{$height});
     height: $scrim;
     background: linear-gradient(180deg, transparent, $white);
-
-    .gl-dark & {
-      background: linear-gradient(180deg, transparent, $black);
-    }
   }
 }