Merge branch '23849-pipeline-graph-bug' into 'master'

Only remove right connector of first build of last stage

Closes #23849

See merge request !7179
Signed-off-by: Rémy Coutable <remy@rymai.me>

app/assets/stylesheets/pages/pipelines.scss

@@ -570,7 +570,7 @@
     .build {
       // Remove right connecting horizontal line from first build in last stage
       &:first-child {
-        &::after, &::before {
+        &::after {
           border: none;
         }
       }