Fix deprecation message appearing in CLI context with PHP 8.1

[driehle]

Extracted into a separate PR upon request in #64 (comment).

This fixes another deprecation only related to CLI dumping. Please consider the following sample:

<?php

declare(strict_types=1);

require_once 'vendor/autoload.php';

Krumo::dump(null);

The output is as follows, with PHP 8.1 there is a deprecation:

driehle@DESKTOP-DENNIS:~/tmp$ php8.0 test.php
--------------------------------------------------------------------------------
NULL

Called from /home/driehle/tmp/test.php, line 7  (Krumo version 0.6.1)
--------------------------------------------------------------------------------

driehle@DESKTOP-DENNIS:~/tmp$ php8.1 test.php
--------------------------------------------------------------------------------
NULLPHP Deprecated:  trim(): Passing null to parameter #1 ($string) of type string is deprecated in /home/driehle/tmp/vendor/mmucklo/krumo/class.krumo.php on line 1611


Called from /home/driehle/tmp/test.php, line 7  (Krumo version 0.6.1)
--------------------------------------------------------------------------------

[driehle]

@scottchiefbaker re/ comment #64 (comment)

The trim() should go in a separate PR. Probably makes more sense to do:

$out = var_export($i) ?? "";

Instead of casting to a string? I dunno, what do you think? If you get these two issues separated I'll work on landing them ASAP.

I like this as well, but according to composer.json the minimum version for Krumo is 5.2.17 and ?? is only available with PHP 7.0, see https://3v4l.org/v2obQ.

We could, however, increase the minimum version to PHP 7.0 and continue with that syntax. This should then be a minor release (0.7.0) and not a patch release (0.6.2).

[scottchiefbaker]

We should definitely bump the support PHP version to 7.0 as a minimum. If you update the composer.json and the trim() line I will gladly land this fix.

[driehle]

Done

[scottchiefbaker]

Looks good!