fix: caret position when editing block comments (#9153)

Author: maribethb

core/bubbles/textinput_bubble.ts

@@ -173,6 +173,10 @@ export class TextInputBubble extends Bubble {
     browserEvents.conditionalBind(textArea, 'wheel', this, (e: Event) => {
       e.stopPropagation();
     });
+    // Don't let the pointerdown event get to the workspace.
+    browserEvents.conditionalBind(textArea, 'pointerdown', this, (e: Event) => {
+      e.stopPropagation();
+    });
 
     browserEvents.conditionalBind(textArea, 'change', this, this.onTextChange);
   }