Replace onion pattern divs/css with tiling SVG

Replace with tiling background svg:

• #40613 (comment 2753711)

changed milestone to %Tor Browser: 11.0 Issues with previous release

added Doing UX FF91-esr labels

assigned to @richard

mentioned in issue #40487 (closed)

New Hotness:

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mentioned in issue #40461 (closed)

mentioned in issue torbutton#40050 (closed)

mentioned in merge request torbutton!59 (merged)

Here are the values I've ended up with!

Light theme

• Base value: Grey 30 / 100%
• SVG alpha: 30% / 15%

Dark theme

• Base value: Grey 60 / 100%
• SVG alpha: 30% / 15%

about:tor

• Base value: White / 20%
• SVG alpha: 30% / 15%

I also slightly increased the width of the stroke so it's easier on the eye, but if it takes more than a couple of minutes to update feel free to ignore and continue using the current version :)

Here's the updated asset:

• repeatable-onion-pattern.svg

(Or if you prefer, feel free to teach me how to swap in/out the FF vars and I can take care of that!)

Thanks @richard!

Ok final screenshots for your enjoyment:

• System:
• Light:
• Dark:
• Aspenglow:
• about:tor:

closed

removed Doing label

mentioned in merge request !210 (merged)