Describe the bug
Etherpad should wait the whole pad to load before scrolling to anchor/line.
Especially with contents like images (am using ep_image_upload)
Not exactly a 'bug', near a feature...

To Reproduce

1. create pad with text (more than screen height)
2. add image
3. clic on the number line (after the image)
4. reload page (with #L100 in url)
5. Back to Etherpad, scroll.js do the job before content loaded
6. result : wrong line/viewport for the user

Expected behavior
I except to see the line the user clic in (without ambiguity)

Server (please complete the following information):

• Version number: 1.9.0 - Git sha: 48381de
• OS: Rasbian ( Linux RaspServer 5.15.76-v8+ )
• Node.js version : v18.15.0
• npm version : 9.5.0
• Is the server free of plugins: tested with ep_image_upload

Desktop (please complete the following information):

• OS: Linux FrameworkPC 5.15.94-1-MANJARO
• Browser Firefox
• Version 110.0

Additional context
I also search solution here : #4554