PHP 8.x Support

[szainmehdi]

Makes this package installable on PHP 8.x, and adds PHP 8.1 to the testing matrix.

[khepin]

use statement got added, but this doesn't seem to be used anywhere in the file

[szainmehdi]

It's actually used here

laravel-mutate/src/Database/EloquentBuilder.php

Lines 69 to 72 in aab32b1

	public function whereKey($id)
	{
	if (is_array($id) || $id instanceof Arrayable) {
	$this->whereIn($this->model->getQualifiedKeyName(), $id);

This is technically a bugfix ;)

[khepin]

What behavior are we driving from this? The composer.json still says php 7.x is OK. On 7, this will be a comment does that cause a problem?

[szainmehdi]

Adding this attribute is necessary to prevent these errors in PHPStan (also, PHP will throw an error when executing this code in PHP 8.1 if this attribute is not added or the return type is not set correctly.

 ------ -------------------------------------------------------------------------------------------------------------------------------------------------------------------
  Line   src/MutatorProvider.php
 ------ -------------------------------------------------------------------------------------------------------------------------------------------------------------------
  69     Return type mixed of method Weebly\Mutate\MutatorProvider::offsetExists() is not covariant with tentative return type bool of method ArrayAccess::offsetExists().
         💡 Make it covariant, or use the #[\ReturnTypeWillChange] attribute to temporarily suppress the error.
  89     Return type mixed of method Weebly\Mutate\MutatorProvider::offsetSet() is not covariant with tentative return type void of method ArrayAccess::offsetSet().
         💡 Make it covariant, or use the #[\ReturnTypeWillChange] attribute to temporarily suppress the error.
  97     Return type mixed of method Weebly\Mutate\MutatorProvider::offsetUnset() is not covariant with tentative return type void of method ArrayAccess::offsetUnset().
         💡 Make it covariant, or use the #[\ReturnTypeWillChange] attribute to temporarily suppress the error.
 ------ -------------------------------------------------------------------------------------------------------------------------------------------------------------------

In older PHP versions, since it is # prefixed, it will be ignored as a comment and will be perfectly fine, since it doesn't apply anyway.