Tests refresh the main database

Hello, I have a problem using tests. When I run them, they update my main database. The configuration is as follows:

1.config/database.php

            'driver' => 'mysql',
            'url' => env('DB_URL'),
            'host' => env('DB_HOST', '127.0.0.1'),
            'port' => env('DB_PORT', '3306'),
            'database' => env('DB_DATABASE', 'laravel'),
            'username' => env('DB_USERNAME', 'root'),
            'password' => env('DB_PASSWORD', ''),
            'unix_socket' => env('DB_SOCKET', ''),
            'charset' => env('DB_CHARSET', 'utf8mb4'),
            'collation' => env('DB_COLLATION', 'utf8mb4_general_ci'),
            'prefix' => '',
            'prefix_indexes' => true,
            'strict' => true,
            'engine' => null,
            'options' => extension_loaded('pdo_mysql') ? array_filter([
                PDO::MYSQL_ATTR_SSL_CA => env('MYSQL_ATTR_SSL_CA'),
            ]) : [],
        ],

        'mysql_testing' => [
            'driver' => 'mysql',
            'host' => env('DB_HOST', '127.0.0.1'),
            'port' => env('DB_PORT', '3306'),
            'database' => 'imt0245_test',
            'username' => env('DB_USERNAME', 'laravel'),
            'password' => env('DB_PASSWORD', ''),
            'unix_socket' => env('DB_SOCKET', ''),
            'charset' => env('DB_CHARSET', 'utf8mb4'),
            'collation' => env('DB_COLLATION', 'utf8mb4_general_ci'),
            'prefix' => '',
            'prefix_indexes' => true,
            'strict' => true,
            'engine' => null,
            'options' => extension_loaded('pdo_mysql') ? array_filter([
                PDO::MYSQL_ATTR_SSL_CA => env('MYSQL_ATTR_SSL_CA'),
            ]) : [],
        ], 

phpunit.xml

<?xml version="1.0" encoding="UTF-8"?>
<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:noNamespaceSchemaLocation="vendor/phpunit/phpunit/phpunit.xsd"
         bootstrap="vendor/autoload.php"
         colors="true"
>
    <testsuites>
        <testsuite name="Unit">
            <directory>tests/Unit</directory>
        </testsuite>
        <testsuite name="Feature">
            <directory>tests/Feature</directory>
        </testsuite>
    </testsuites>
    <source>
        <include>
            <directory>app</directory>
        </include>
    </source>
    <php>
        <env name="APP_ENV" value="testing"/>
        <env name="APP_MAINTENANCE_DRIVER" value="file"/>
        <env name="BCRYPT_ROUNDS" value="4"/>
        <env name="CACHE_STORE" value="array"/>
        <env name="DB_CONNECTION" value="mysql_testing"/>
        <env name="DB_DATABASE" value="imt0245_test"/>
        <env name="MAIL_MAILER" value="array"/>
        <env name="PULSE_ENABLED" value="false"/>
        <env name="QUEUE_CONNECTION" value="sync"/>
        <env name="SESSION_DRIVER" value="array"/>
        <env name="TELESCOPE_ENABLED" value="false"/>
    </php>
</phpunit>

.env

DB_CONNECTION=mysql
DB_HOST=127.0.0.1
DB_PORT=3306
DB_DATABASE=imt0245
DB_USERNAME=****
DB_PASSWORD=****

.env.testing

DB_CONNECTION=mysql_testing
DB_HOST=127.0.0.1
DB_PORT=3306
DB_DATABASE=imt0245_test
DB_USERNAME=*****
DB_PASSWORD=*****

Execution command is

php artisan test tests/Feature/ExampleTest.php

Thank you for your answers <3