Fix coveralls failing on build re-runs #669

Job	Run time
Code style and static analysis	38s
Code style and static analysis	41s
Code style and static analysis	39s
Markdown link check	15s
Markdown link check	16s
Markdown link check	15s
PHP 7.3	42s
PHP 7.3	43s
PHP 7.3	36s
PHP 7.4	36s
PHP 7.4	36s
PHP 7.4	33s
PHP 8.0	33s
PHP 8.0	33s
PHP 8.0	40s
PHP 8.1	31s
PHP 8.1	33s
PHP 8.1	33s
PHP 7.3 --prefer-lowest --prefer-stable	42s
PHP 7.3 --prefer-lowest --prefer-stable	39s
PHP 7.3 --prefer-lowest --prefer-stable	38s
	11m 52s

Provide feedback