Plugins not working as intended

[UltraBlackLinux]

Describe the bug
Installing plugins does not really work properly. Toolbar buttons for example don't exist

To Reproduce
Steps to reproduce the behavior:

1. Install a Plugin, like ep_align (in this case from the admin interface)

Expected behavior
There should be toolbar buttons.

Additional information
I have tried to manually add the buttons to the toolbar and it seems like plugins are not really installed. I just get some error which probably means that the plugin is missing

I don't have the time to do a lot of testing. The fact that etherpad downloads all plugins every time it's launched makes it incredibly slow. Once restart takes ~5 minutes.

Server (please complete the following information):

• Etherpad version: 4b96ff6
• OS: Ubuntu Server 22.04 LTS
• Node.js version (node --version): v12.22.9
• npm version (npm --version): 8.5.1
• Is the server free of plugins: apparently

Desktop (please complete the following information):

• OS: Arch Linux
• Browser Librewolf
• Version 105.0.3

Additional context
Add any other context about the problem here.

[JohnMcLear]

See #5643

[SamTV12345]

This is solved :)