Customizer: Remove date filter from the Header/Background Image upload frames.

Adds an option to `wp.media.view.AttachmentsBrowser` to hide the date filter added in [29813].

Merges [30872] to the 4.1 branch.

See #30689.

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Customizer: Import missing `wp.customize.Control.prototype._toggleActive`.

Check also if `completeCallback` is set before calling it.

Merges [30871] to the 4.1 branch.

Props westonruter.
See #30701.

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Fix menu shakiness when over-scrolling in Chrome and Safari on MacOS.

Merges [30844] to the 4.1 branch.

See #30692.

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Improve the fix for menu shakiness when over-scrolling. Recalculate heights on editor auto-resize.

Merges [30852] to the 4.1 branch.

See #30692.

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Background Updates: Pass back whether Group Writable support is being leveraged for an update to the WordPress.org API.

Merges [30860] to the 4.1 branch.

See #30245

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Make the DFW paragraph on the About page narrower to mitigate an orphan in Firefox.

Merges [30921] to the 4.1 branch.

See #30435
Props melchoyce

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