Remove --debug option removed in PHPUnit 10 for continuous integration tests

Error:
  + ../vendor/bin/phpunit --configuration phpunit.xml --debug --verbose
  PHPUnit 10.0.1 by Sebastian Bergmann and contributors.

  Unknown option "--debug"

tests/ci.sh

@@ -93,7 +93,6 @@ fi
 "${phpunit_to_use}" --version
 "${phpunit_to_use}" \
     --configuration "phpunit.xml" \
-    --debug \
     --verbose
 if [[ "${?}" -ne 0 ]]; then
     echo "Error: phpunit command failed"

tests/run.sh

@@ -124,5 +124,5 @@ done
 if [[ "${CI_PHP_FUTURE_RELEASE}" != "true" ]]; then
     exit "${#errors[@]}"
 elif [[ "${#errors[@]}" -ne 0 ]]; then
-    echo "One or more tests failed, but allowed as CI_PHP_FUTURE_RELEASE is on for PHP version ${CI_PHP_VERSION}."
+    echo "One or more tests failed, but allowed as the CI_PHP_FUTURE_RELEASE flag is on for PHP version ${CI_PHP_VERSION}."
 fi