Implicitly marking parameter $len as nullable is deprecated

[Rockburner]

When using error_reporting(E_ALL), and ini_set('display_errors', 'on'); in a codebase using PHP 8.4 we're getting the following deprecation notice:

Rollbar\Utilities::validateString(): Implicitly marking parameter $len as nullable is deprecated, the explicit nullable type must be used instead

The fix is relatively easy:

line 32 : int|array $len = null,

change to

line 32: int|array|null $len = null,

Looks like most of the null declarations are already in place, I'm assuming this was just missed.

[linear]

SDK-475 Implicitly marking parameter $len as nullable is deprecated