Always open List View: disable sidebar animation when preference is enabled

[afercia]

Description

Noticed while working on #69147 / #69190

When the ''Always open List View:' preferences ie enabled, the sidebar animation on first page load is a very distrqacting and unexpected experience. As an useer, I don't want to see anything that 'moves' on my screen when the page loads.

The animation is even more noticeable and disturbing with browsers that make animations run 'smoother' for example with Safari. Video to illustrate the behavior with Safari:

Screen.Recording.2025-02-19.at.08.51.45.mov

To my understanding, the animation is set on the secondary sidebar in the interface package.

gutenberg/packages/interface/src/components/interface-skeleton/index.js

Lines 166 to 201 in 90ee09a

	<AnimatePresence initial={ false }>
	{ !! secondarySidebar && (
	<NavigableRegion
	className="interface-interface-skeleton__secondary-sidebar"
	ariaLabel={ mergedLabels.secondarySidebar }
	as={ motion.div }
	initial="closed"
	animate="open"
	exit="closed"
	variants={ {
	open: { width: secondarySidebarSize.width },
	closed: { width: 0 },
	} }
	transition={ defaultTransition }
	>
	<motion.div
	style={ {
	position: 'absolute',
	width: isMobileViewport
	? '100vw'
	: 'fit-content',
	height: '100%',
	left: 0,
	} }
	variants={ {
	open: { x: 0 },
	closed: { x: '-100%' },
	} }
	transition={ defaultTransition }
	>
	{ secondarySidebarResizeListener }
	{ secondarySidebar }
	</motion.div>
	</NavigableRegion>
	) }
	</AnimatePresence>

So that the animation works on any panel within the sidebar, for example also for the main inserter. Only the List View panel has a preference to stay always open though.

Ideally, when 'Always open List View' is enabled, the animation should not run on first page load. After that, it should run when users close and reopen the list view manually.

Step-by-step reproduction instructions

• Go to the post editor > Options > Preferences and enable the preference 'Always open List View'.
• Exit the editor and to the WP admin 'Posts' page.
• Click any post to edit it in the editor.
• Observe the jarring animation on page load.

Screenshots, screen recording, code snippet

No response

Environment info

No response

Please confirm that you have searched existing issues in the repo.

• Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

• Yes

Please confirm which theme type you used for testing.

• Block
• Classic
• Hybrid (e.g. classic with theme.json)
• Not sure