Upload buttons cannot be accessed with the keyboard

[MMK21Hub]

Describe the bug

In the General tab of project settings, the user can add/replace the project's icon by clicking on a button ("Upload icon"). In addition, gallery images can be added by clicking the "Upload an image" button in the Gallery tab of a project. However, these buttons cannot be used with the keyboard, making these actions impossible if you rely on keyboard interaction.

Steps to reproduce

1. Go to the Gallery tab of a project that you own
2. Press the Tab key a few times to try to move your focus to the "Upload an image" button
   → ❌ Focus skips from the "Settings" button to the "Edit" button on the first gallery image (if one exists)

Expected behavior

The "Upload an image" button would be focused on after the settings button.

Additional context

No response

[MMK21Hub]

Discovered while testing #1695