fix(popup): misalignment in popup close button icon

[choejwoo]

related to #575 Closes argoproj/argo-cd#19372

Hello, While I was working on fixing a UI issue, I noticed that the popup had a close button icon alignment problem. However, according to PR #575, this misalignment was already fixed. It seems that the button, which was previously positioned lower, was moved up in that PR. I'm not sure when it happened, but it seems that the button was moved up again. Still, my Argo CD instance shows the issue, as you can see, so I fixed it to ensure the icon is properly positioned. I tried both Edge and Chrome, but it doesn’t seem to be a browser issue.

Before

After

Please check it out and let me know if this problem only occurs in my UI. I’ve attached screenshots of my UI. Thanks!