Fix unknonw div props in context menu (#9277)

src/components/structures/ContextMenu.tsx

@@ -397,6 +397,13 @@ export default class ContextMenu extends React.PureComponent<IProps, IState> {
             </FocusLock>;
         }
 
+        // filter props that are invalid for DOM elements
+        const {
+            hasBackground: _hasBackground, // eslint-disable-line @typescript-eslint/no-unused-vars
+            onFinished: _onFinished, // eslint-disable-line @typescript-eslint/no-unused-vars
+            ...divProps
+        } = props;
+
         return (
             <RovingTabIndexProvider handleHomeEnd handleUpDown onKeyDown={this.onKeyDown}>
                 { ({ onKeyDownHandler }) => (
@@ -413,7 +420,7 @@ export default class ContextMenu extends React.PureComponent<IProps, IState> {
                             style={menuStyle}
                             ref={this.collectContextMenuRect}
                             role={managed ? "menu" : undefined}
-                            {...props}
+                            {...divProps}
                         >
                             { body }
                         </div>

test/components/views/context_menus/__snapshots__/SpaceContextMenu-test.tsx.snap

@@ -194,8 +194,6 @@ exports[`<SpaceContextMenu /> renders menu correctly 1`] = `
             />
             <div
               className="mx_ContextualMenu"
-              hasBackground={true}
-              onFinished={[MockFunction]}
               role="menu"
               style={Object {}}
             >