Darkmode is not consistent, page flashes in default mode during page load

[sirtux]

Environment

• Python version: 3.9
• Nautobot version: v1.4.0a2

Steps to Reproduce

1. Enable dark mode
2. Go to any other page then the current one

Expected Behavior

Dark mode is permanent active

Observed Behavior

During load, I can see the light mode pop up for less then a second before it switches to dark mode.
This breaks the user experience and also hurts in the eye.

[lampwins]

@sirtux can you confirm what browser/os and version you are seeing this on?

[lampwins]

Actually just confirmed this on https://next.demo.nautobot.com/dcim/devices/?per_page=1000

Seems this is because we load the theme JS after content (which is a general JS best practice), but that is biting us here.

[gsnider2195]

Could we switch this to on dom ready instead of page load complete?