fix upload file issue (#3962)

skyvern/webeye/utils/dom.py

@@ -620,6 +620,13 @@ class SkyvernElement:
             index += 1
         return None
 
+    async def find_file_input_in_children(self) -> Locator | None:
+        """Sometime the file input is invisible on the page, so it won't exist in the element tree, but it can be found in the DOM."""
+        locator = self.get_locator().locator('input[type="file"]')
+        if await locator.count() != 1:
+            return None
+        return locator
+
     async def get_attr(
         self,
         attr_name: str,