Updates style of arrown in downstream pipeline

app/assets/stylesheets/pages/pipelines.scss

@@ -1003,10 +1003,10 @@ a.linked-pipeline-mini-item {
   .arrow-icon {
     display: inline-block;
     vertical-align: middle;
-    margin: -4px 2px 0 0;
+    margin: -2px 2px 0 0;
 
     svg {
-      fill: $gray-darkest;
+      fill: $border-color;
     }
   }
 

ee/changelogs/unreleased/3572-downstream-pipeline.yml

+---
+title: Updates style of arrown in downstream pipeline
+merge_request: 5172
+author:
+type: fixed