Close pipeline UI shouldn't scroll with overview

[mrjoel]

Jenkins and plugins versions report

pipeline-graph-view-plugin 191.vc6da_9d3eb_70a

What Operating System are you using (both controller, and any agents involved in the problem)?

Linux

Reproduction steps

1. Have pipeline with many steps requiring horizontal scrolling
2. From Pipeline overview page, click Expand pipeline
3. In expanded pipeline view, scroll to the right
4. Notice that the Close pipeline icon scrolls with the content

Expected Results

The Close pipeline icon should remain fixed in the upper-right of the view

Actual Results

the Close pipeline icon scrolls with the content

Anything else?

No response

[mrjoel]