This PR updates the PHPUnit configuration to fix the schema deprecation warning when running the test suite on the latest version of PHPUnit.
There was 1 PHPUnit test runner deprecation:
1) Your XML configuration validates against a deprecated schema. Migrate your XML configuration using "--migrate-configuration"!
It introduces new warnings on the older PHPUnit versions in the CI matrix, but I'm favouring the latest ones.
This PR updates the PHPUnit configuration to fix the schema deprecation warning when running the test suite on the latest version of PHPUnit.
It introduces new warnings on the older PHPUnit versions in the CI matrix, but I'm favouring the latest ones.