Downstream pipeline mini graph has incorrect styles for connecting bars

After some recent change a downstream pipeline mini graph is shown incorrectly:

Notice the left part has connecting bars in between circles, but the right part doesn't have them.

Here's how it's supposed to look:

These bars are shown out of place on the merge request page (notice a 3px bar on the right):

This is because a position: relative was removed from some of the parent elements of these circles, thus causing a misplacement.

To reproduce:

1. Visit any merge request with a downstream pipeline running
2. Observe an out of place grey bar in the top right corner of the page