remove generic type from merge function

Author: dcastil

packages/editor/src/EditorProvider.ts

@@ -3,8 +3,7 @@ import { jsx, Context, useThemeUI, merge, Theme } from 'theme-ui'
 import { ThemeContext as Emotion } from '@emotion/core'
 import { EditorContextValue } from './types'
 
-const reducer = (state: Theme, next: Partial<Theme>) =>
-  merge<Theme>(state, next)
+const reducer = (state: Theme, next: Partial<Theme>) => merge(state, next)
 
 export interface EditorProviderProps {
   children?: React.ReactNode