Laravel not using the test DB connection

Hi there

I want Laravel to run tests in my test DB connection but inside a test dd(config('database.default'), env('DB_CONNECTION')); gives:

"mysql"
"mysql"

My config/database.php:

<?php

use Illuminate\Database\DBAL\TimestampType;

return [
    'default' => env('DB_CONNECTION', 'mysql'),
    'connections' => [
        'mysql' => [
            'driver' => 'mysql',
            'url' => env('DATABASE_URL'),
            'host' => env('DB_HOST', 'mysql'),
            'port' => env('DB_PORT', '3306'),
            'database' => env('DB_DATABASE', 'forge'),
            'username' => env('DB_USERNAME', 'forge'),
            'password' => env('DB_PASSWORD', 'forge'),
            'unix_socket' => env('DB_SOCKET', ''),
            'charset' => 'utf8mb4',
            'collation' => 'utf8mb4_unicode_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'),
            ]) : [],
        ],

        'testing' => [
            'driver' => 'mysql',
            'host' => 'test_mysql', // see docker-compose.dev.yml
            'port' => '3307', // see docker-compose.dev.yml
            'database' => 'TEST_DB', // see docker-compose.dev.yml
            'username' => env('DB_USERNAME', 'forge'),
            'password' => env('DB_PASSWORD', 'forge'),
            'unix_socket' => env('DB_SOCKET', ''),
            'charset' => 'utf8mb4',
            'collation' => 'utf8mb4_unicode_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'),
            ]) : [],
        ],

My 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"
         stopOnFailure="true"
         stopOnError="true"
>
  <testsuites>
    <testsuite name="Unit">
      <directory suffix="Test.php">./tests/Unit</directory>
    </testsuite>
    <testsuite name="Feature">
      <directory suffix="Test.php">./tests/Feature</directory>
    </testsuite>
  </testsuites>
  <php>
    <env name="APP_ENV" value="testing" force="true" />
    <env name="DB_CONNECTION" value="testing" force="true" />
    <env name="DB_HOST" value="test_mysql" force="true" />
    <env name="DB_PORT" value="3307" force="true" />
    <env name="DB_DATABASE" value="TEST_DB" force="true" />
    <env name="DB_USERNAME" value="forge" force="true" />
    <env name="DB_PASSWORD" value="forge" force="true" />
    <env name="BCRYPT_ROUNDS" value="4"/>
    <env name="CACHE_DRIVER" value="redis"/>
    <env name="MAIL_MAILER" value="array"/>
    <env name="QUEUE_CONNECTION" value="sync"/>
    <env name="SESSION_DRIVER" value="array"/>
    <env name="TELESCOPE_ENABLED" value="false"/>
  </php>
</phpunit>

My .env.testing

APP_KEY=[SOME_KEY]
APP_ENV=testing
CACHE_DRIVER=redis
APP_DEBUG=true
DB_CONNECTION=testing

The setup is containerized:

version: "3.9"
services:

  backend:
    container_name: backend
    image: laravel
    build:
      context: ./../
      dockerfile: ./docker/Dockerfile
    depends_on:
      - mysql
    extra_hosts:
      - "host.docker.internal:host-gateway"
    ports:
      - "80:80"
    volumes:
      - ./../:/var/www/html
      - anonymousvolume1:/var/www/html/vendor
      - /var/www/html/node_modules
    env_file:
      - ./../.env
    environment:
      - CONTAINER_ROLE=app
      - APP_DEBUG=true
    networks:
      - pms-network

  mysql:
    container_name: mysql
    image: mariadb:10.6.12
    ports:
      - "3306:3306"
    volumes:
      - ./../mysql/:/docker-entrypoint-initdb.d
    environment:
      MYSQL_DATABASE: forge
      MYSQL_ROOT_PASSWORD: forge
      MYSQL_USER: forge
      MYSQL_PASSWORD: forge
    networks:
      - pms-network

  test_mysql:
    container_name: test_mysql
    image: mariadb:10.6.12
    ports:
      - "3307:3306"
    volumes:
      - ./../mysql/:/docker-entrypoint-initdb.d
    environment:
      MYSQL_DATABASE: TEST_DB
      MYSQL_ROOT_PASSWORD: forge
      MYSQL_USER: forge
      MYSQL_PASSWORD: forge
    networks:
      - pms-network

networks:
  pms-network:
    driver: bridge
volumes:
  anonymousvolume1:
    driver: local