Packman: "Sign in" button border is not fully displayed in the UI

Steps to reproduce:

1. Open or create a project
2. Go to "Window" ->"Package Manager"
3. Select "My Assets" in the navigation panel
4. Make a sign out from the engine

Expected Result: A tidy "Sign in" button should be displayed to sign in to your Unity account.

Actual Result: A button is displayed, but its borders are not fully displayed in the UI. The screenshot is added in the "Attachments" section.

Reproducible with:  2021.3.32f1, 2022.3.13f1, 2023.1.20f1, 2023.2.0f1, 2023.3.0a14.

More info: https://unityeditordesignsystem.unity.com/components/button#Basic-Button