Improved session stability, accessibility, and Studio performance

This release fixes a session management issue that could cause an unexpected studio crash, improves accessibility in several components, and eliminates unnecessary API requests for better performance.

• Updates the bundled Sanity CLI dependency to 8.9.1.
• Fixes an issue where signing in could immediately sign you out if multiple Studio tabs were open.
• Fixes an issue where an expired session could crash the Studio with an "EventSource connection failed" error.
• Fixes invalid DOM attributes (margins, ratio, open, isSelected, asset) from being rendered by a few internal styled components in the presence overlay, image tool input, file asset source list and the Details component. The file asset source list rows now report their real selection state through aria-selected.
• The workspace menu no longer shifts its header on first open. The studio also stops issuing a redundant /projects/<id> request each time the menu is first opened; the project name now comes from the request already made at boot.