run/laravel tests not configured correctly

[glasnt]

Identified in https://github.com/GoogleCloudPlatform/php-docs-samples/pull/1931

https://github.com/GoogleCloudPlatform/php-docs-samples/blob/main/run/laravel/phpunit.xml#L9 is referencing a file that doesn't exist.

[glasnt]

Kokoro expects a /test/ folder. (in some cases, https://source.cloud.google.com/results/invocations/9faf8443-ec1a-4363-ab31-9f52a139cca6/targets/cloud-devrel%2Fphp-docs-samples%2Fpresubmit%2Fphp80/log Latest error says find: 'run/laravel/test/': No such file or directory which I think maps to the find command in https://github.com/GoogleCloudPlatform/php-docs-samples/blob/main/testing/run_test_suite.sh#L165)

Laravel hardcodes a /tests/ folder https://github.com/laravel/framework/blob/9.x/src/Illuminate/Foundation/Console/TestMakeCommand.php#L84

[bshaffer]

@glasnt this should be fixed in #1991 - I updated the script to hide the "No such file or directory" error output, and to check in both test and tests dirs.