Deprecated function: json_decode()

Problem/Motivation

Getting Error while running the page where the poll setup happened.

Deprecated function: json_decode(): Passing null to parameter #1 ($json) of type string is deprecated in Drupal\poll\PollVoteStorage->getUserVote() (line 169 of /docroot/modules/contrib/poll/src/PollVoteStorage.php) #0 /docroot/core/includes/bootstrap.inc(164): _drupal_error_handler_real(8192, 'json_decode(): ...', '.../', 169)

This error is coming after php version upgrade of 8.1, Drupal version 10.x.

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes