Unit tests fail. Class 'org\bovigo\vfs\vfsStream' not found

In case this helps anyone who prefers using lando for local development.

name: migrate-tools
recipe: drupal9
config:
  php: '7.4'
  via: apache:2.4
  webroot: web
  database: mariadb:10.4
  xdebug: false
services:
  # Replaces default lando MariaDB image with arm64 (Apple M1) compatible one.
  # TODO: remove database service overrides once lando is updated.
  database:
    type: compose
    services:
      image: mariadb:10.4
      command: docker-entrypoint.sh mariadbd
      restart: always
      ports:
        - '3306'
      environment:
        MARIADB_ALLOW_EMPTY_ROOT_PASSWORD: 'true'
        MARIADB_DATABASE: drupal9
        MYSQL_DATABASE: drupal9
        MARIADB_USER: drupal9
        MARIADB_PASSWORD: drupal9
  appserver:
    overrides:
      environment:
        SIMPLETEST_DB: 'mysql://drupal9:drupal9@database/drupal9'
        SIMPLETEST_BASE_URL: 'http://appserver'
        MINK_DRIVER_ARGS_WEBDRIVER: '["chrome", {"browserName":"chrome","chromeOptions":{"args":["--disable-gpu","--disable-dev-shm-usage","--headless","--no-sandbox"],"w3c":false}},"http://chromedriver:4444/wd/hub"]'
        XDEBUG_MODE: debug
      volumes:
        # Don't share our host working directory as /app. We want /app empty for composer.
        - /app
        # Instead share our host working directory as a standalone package.
        - .:/usr/local/migrate_tools
    build:
      - git clone --depth 1 --branch 9.4.5 https://github.com/drupal/recommended-project.git /app
      - composer config repositories.localdev path /usr/local/migrate_tools
      - composer require --no-update liuggio/fastest:1.11.0
      - composer require --no-update "behat/behat"
      - composer require --no-update "behat/mink:^1.8"
      - composer require --no-update "behat/mink-goutte-driver:^1.2"
      - composer require --no-update "behat/mink-selenium2-driver:^1.4"
      - composer require --no-update "phpspec/prophecy-phpunit:^2"
      - composer require --no-update "symfony/phpunit-bridge:^6.1"
      - composer require --no-update "mikey179/vfsstream"
      - composer require --no-update "phpunit/phpunit:^9.1"
      - composer require --no-update "drush/drush:>=11"
      - composer require --no-update "drupal/migrate_source_csv:>=3"
      - composer require --no-update "drupal/migrate_plus:>=5"
      - composer require --no-update drupal/migrate_tools:\*@dev
      - composer install
      - composer update
  chromedriver:
    type: compose
    services:
      image: seleniarm/standalone-chromium:4.1.4-20220429
      command: /opt/bin/entry_point.sh

tooling:
  # Provide a command to install Drupal.
  install:
    service: appserver
    cmd:
      - /app/vendor/bin/drush --root=/app/web site:install --account-mail=noreply@example.com --account-name=admin --account-pass=admin --db-url=mysql://drupal9:drupal9@database:3306/drupal9 -y --verbose
      - /app/vendor/bin/drush en -y migrate_tools

  # Provide Drush tooling to automatically know the Drupal root.
  drush:
    service: appserver
    cmd: /app/vendor/bin/drush --root=/app/web
  phpunit:
    service: appserver
    cmd: /app/vendor/bin/phpunit --configuration /app/web/modules/contrib/migrate_tools/phpunit.xml.dist /app/web/modules/contrib/migrate_tools

And the corresponding phpunit.xml.dist

<?xml version="1.0" encoding="UTF-8"?>
<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" bootstrap="/app/web/core/tests/bootstrap.php" colors="true" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/9.3/phpunit.xsd">
  <coverage processUncoveredFiles="true">
    <include>
      <directory>./modules</directory>
    </include>
    <exclude>
      <directory suffix="Test.php">./</directory>
      <directory suffix="TestBase.php">./</directory>
    </exclude>
  </coverage>
  <php>
    <!-- Set error reporting to E_ALL. -->
    <ini name="error_reporting" value="32767"/>
    <!-- Do not limit the amount of memory tests take to run. -->
    <ini name="memory_limit" value="-1"/>
  </php>
  <testsuites>
    <testsuite name="MigrateToolsTest">
      <directory>./tests</directory>
      <directory>./modules</directory>
    </testsuite>
  </testsuites>
  <!-- Filter for coverage reports. -->
</phpunit>

Once you have lando installed
Inside the folder where you cloned a copy of migrate_tools run
lando start
lando install
lando phpunit

Which outputs

➜  migrate_tools git:(6.0.x) ✗ lando phpunit
PHPUnit 9.6.7 by Sebastian Bergmann and contributors.

....................................                              36 / 36 (100%)

Time: 00:59.423, Memory: 10.00 MB

OK (36 tests, 328 assertions)