Only pay attention to focusout of math-elements in order to allow the…

… 'manual' focusout policy added in issue #1914 to be respected. (#2239)

Co-authored-by: Dan Bradley <WasteEnemy@gmail.com>

src/virtual-keyboard/virtual-keyboard.ts

@@ -302,6 +302,7 @@ export class VirtualKeyboard implements VirtualKeyboardInterface, EventTarget {
     });
 
     document.addEventListener('focusout', (evt) => {
+      if ((evt.target as HTMLElement)?.tagName?.toLowerCase() !== 'math-field') return;
       const target = evt.target as MathfieldElement;
       if (target.mathVirtualKeyboardPolicy !== 'manual') {
         // If after a short delay the active element is no longer