v85.1.0

• Updated EuiComboBox's options to accept option.append and option.prepend props (#6953)
• Updated deprecated .substr() usages to .substring() (#6954)
• Updated EuiInlineEdit's read mode button to include a title tooltip, increasing readability of truncated text (#6966)

Bug fixes

• Fixed EuiFilterGroup's responsive styles (#6983)

Deprecations

• Deprecated EuiFilterSelectItem; Use EuiSelectable instead (#6982)

CSS-in-JS conversions

• Converted EuiFilterSelectItem to Emotion (#6982)
• Removed .euiFilterSelect__items CSS; Use EuiSelectable instead (#6982)
• Removed .euiFilterSelect__note and .euiFilterSelect__noteContent CSS; Use EuiSelectableMessage instead (#6982)
• Added focus.transparency and focus.backgroundColor theme tokens (#6984)