Your requirements could not be resolved to an installable set of packages. Problem 1 - phpunit/phpunit[9.0.0, ..., 9.2.6] require php ^7.3 -> your php version (5.6.40) does not satisfy that requirement. - phpunit/phpunit[9.3.0, ..., 9.3.8] require php ^7.3 || ^8.0 -> your php version (5.6.40) does not satisfy that requirement. - phpunit/phpunit[9.3.9, ..., 9.6.15] require php >=7.3 -> your php version (5.6.40) does not satisfy that requirement. - Root composer.json requires phpunit/phpunit ~9 -> satisfiable by phpunit/phpunit[9.0.0, ..., 9.6.15].

Process completed with exit code 2.

The following actions uses node12 which is deprecated and will be forced to run on node16: actions/checkout@v2. For more info: https://github.blog/changelog/2023-06-13-github-actions-all-actions-will-run-on-node16-instead-of-node12-by-default/