Revert "Revert "TypeScript Improvement: Use [key: string]: unknown, not [key: string]: any (#3565)""

This reverts commit 81d2f9bb8f.

packages/slate-react/src/components/editable.tsx

@@ -708,7 +708,7 @@ export const Editable = (props: EditableProps) => {
               if (Hotkeys.isRedo(nativeEvent)) {
                 event.preventDefault()
 
-                if (editor.redo) {
+                if (typeof editor.redo === 'function') {
                   editor.redo()
                 }
 
@@ -718,7 +718,7 @@ export const Editable = (props: EditableProps) => {
               if (Hotkeys.isUndo(nativeEvent)) {
                 event.preventDefault()
 
-                if (editor.undo) {
+                if (typeof editor.undo === 'function') {
                   editor.undo()
                 }
 

packages/slate-react/src/components/leaf.tsx

@@ -43,7 +43,7 @@ const Leaf = (props: {
             opacity: '0.333',
           }}
         >
-          {leaf.placeholder}
+          {leaf.placeholder as React.ReactNode}
         </span>
         {children}
       </React.Fragment>

packages/slate-react/src/components/slate.tsx

@@ -17,7 +17,7 @@ export const Slate = (props: {
   value: Node[]
   children: React.ReactNode
   onChange: (value: Node[]) => void
-  [key: string]: any
+  [key: string]: unknown
 }) => {
   const { editor, children, onChange, value, ...rest } = props
   const [key, setKey] = useState(0)