dont run domWalker on scroll

[liady]

Problem: When we scroll the canvas, we always trigger the domWalker, since the check for nothingChanged always returns false (even though it's just the canvas coordinates)

Fix: This is the first fix for this. The simplest fix is to have a special case for SCROLL_CANVAS action - where the domWalker doesn't need to run.

** Note: ** A more complex fix can be to have the actions themselves state whether they need the domWalker to run or not - or have another flag in addition to nothingChanged that checks only for domWalker relevant changes.

Manual Tests: I hereby swear that:

• [X] I opened a hydrogen project and it loaded
• [X] I could navigate to various routes in Preview mode

[github-actions[bot]]

Try me

[relativeci[bot]]

#12002 Bundle Size — 62.35MiB (~+0.01%).

042f2a7(current) vs 6339ece master#11995(baseline)

[!WARNING] Bundle contains 58 duplicate packages – View duplicate packages

Bundle metrics   2 changes 1 regression

	Current #12002	Baseline #11995
Initial JS	45.44MiB(~+0.01%)	45.44MiB
Initial CSS	0B	0B
Cache Invalidation	20.95%	20.93%
Chunks	31	31
Assets	34	34
Modules	4371	4371
Duplicate Modules	503	503
Duplicate Code	30.81%	30.81%
Packages	467	467
Duplicate Packages	58	58

Bundle size by type   2 changes 1 regression 1 improvement

	Current #12002	Baseline #11995
JS	62.34MiB (~+0.01%)	62.34MiB
HTML	10.94KiB (-0.34%)	10.98KiB

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Bundle analysis report Branch fix/scroll-performance Project dashboard

[github-actions[bot]]

Performance test results: