PHPUnit tests are broken on the develop branch

[mdupont]

Describe the Bug

When running tests with composer run-script check --timeout=0 on the develop branch, multiple errors are reported, because of an error in /tests/PhpWord/_includes/AbstractWebServerEmbeddedTest.php

Steps to Reproduce

Running:

$ composer run-script check --timeout=0

will print:

ERRORS!
Tests: 621, Assertions: 1675, Errors: 111.
Script phpunit --color=always --no-coverage handling the test-no-coverage event returned with error code 2
Script @test-no-coverage was called via check

Expected Behavior

Tests should pass on the develop branch, which is the main branch of the project.

Current Behavior

Tests are not passing.

Context

• PHP Version: 7.3 and 7.4
• PHPWord Version: develop branch HEAD