Drupal 9 readiness

Problem/Motivation

Current state of 8.x-2.x branch has following Drupal 9 readiness deprecation notice.

5/5 [▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓] 100%

------ --------------------------------------------------------------------------
Line src/Form/XlsExportForm.php
------ --------------------------------------------------------------------------
67 Call to deprecated function file_upload_max_size():
in drupal:8.7.0 and is removed from drupal:9.0.0.
Use \Drupal\Component\Utility\Environment::getUploadMaxSize() instead.
------ --------------------------------------------------------------------------

[ERROR] Found 1 error

Steps to reproduce

composer require mglaman/drupal-check
./vendor/bin/drupal-check ./web/modules/contrib/xls_views_data_export

Proposed resolution

Fix it