Center build stage columns in pipeline overview

What does this MR do?

Centers the build stage table content and headers in the pipeline view

Are there points in the code the reviewer needs to double check?

Need to check whether it is okay to remove the following (commit that added this property)

.light {
    width: 3px;
}

Why was this MR needed?

Improve UI

Screenshots (if relevant)

Before:

After:

Does this MR meet the acceptance criteria?

• CHANGELOG entry added
• Tests
  • All builds are passing
• Conform by the style guides
• Branch has no merge conflicts with master (if you do - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

Closes #21708 (closed)