File tab content is right-aligned

Created by: mrnugget

• Sourcegraph version:
• Platform information:

Steps to reproduce:

1. Go to https://sourcegraph.com/github.com/sourcegraph/sourcegraph@40c5c3d665983f879465daa32f7d0154db024791/-/blob/enterprise/internal/batches/resolvers/resolver.go#L99-114
2. Look at the files tab:

Expected behavior:

The scrollbar on the bottom of the files tab either is not there (perfect) or scrolled to the left.

Actual behavior:

The content of the tab is horizontally scrollable and it's scrolled to the middle, hiding the beginning of some file names and the end of others.