Fix #10033 PHP Fatal error Uncaught TypeError PHP8

[chris001]

The $array parameter passed to implode($separator, $array) was null.
Previously in PHP 7 and less, this gave only a Notice or Warning error.
In PHP 8+ passing a null array parameter to implode now gives a FATAL error and PHP exits because the call matches a different overloaded function signature, expecting an array in first position, but it gets the separator which is a string.

Description

Fixes bug #10033 when running on PHP 8+

Motivation and Context

PHP 7 and below only emitted a Notice or Warning to the log when you call implode with a NULL for the $array.
PHP 8 and above now will throw an Exception and exit PHP because the call signature matches a different overload and the $separator is passed in where it expects the $array.

How To Test This

See issue.
Basic code example proving this is FATAL on PHP 8+

<?php
$emailsArray = null;
$emailsToLine = implode (',' , $emailsArray);
?>
// When run on PHP 7, this will exit without `Exception`.
// On PHP 8, this will throw a PHP `Fatal uncaught TypeError` Exception

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Final checklist

• My code follows the code style of this project found here.
• My change requires a change to the documentation.
• I have read the How to Contribute guidelines.

[serhiisamko091184]

Hello @chris001 ,
thanks a lot for the contribution.

Regards,
Serhii

[clemente-raposo]

LGTM

[johnM2401]

LGTM

Have checked the "Send Email" action, sending to "Record Email".

Checked on PHP7.4/8.0/8.1/8.2, running the Workflow by both Cron and In-CRM-Saving

All emails sent as expected!