Fix some PHPStan findings in tests

[franmomu]

GuzzleException::getGuzzleException() always returns a TransferException:

Elastica/src/Exception/Connection/GuzzleException.php

Lines 18 to 41 in 4087569

	/**
	* @var TransferException
	*/
	protected $_guzzleException;
	public function __construct(TransferException $guzzleException, ?Request $request = null, ?Response $response = null)
	{
	$this->_guzzleException = $guzzleException;
	$message = $this->getErrorMessage($this->getGuzzleException());
	parent::__construct($message, $request, $response);
	}
	public function getErrorMessage(TransferException $guzzleException): string
	{
	return $guzzleException->getMessage();
	}
	/**
	* @return TransferException
	*/
	public function getGuzzleException(): BaseGuzzleException
	{
	return $this->_guzzleException;
	}

[ruflin]

LGTM. Can you add a changelog?

[ruflin]

Thx

[franmomu]

I'll take a look later at the codecov job because it looks like it works for some jobs: https://github.com/ruflin/Elastica/runs/6775474480?check_suite_focus=true#step:10:27

but not for others:
https://github.com/ruflin/Elastica/runs/6775474648?check_suite_focus=true#step:10:27

Maybe the files gets deleted.

UPDATE: Looks like the report generation failed:

https://github.com/ruflin/Elastica/runs/6775474648?check_suite_focus=true#step:7:30