testing – Druapl, PHPunut and Sqlite

I’m trying to speed up a functional Drupal test.
Given a test…

...
  public function the_front_page_loads_for_anonymous_users() {
    $this->config('system.site')
      ->set('page.front', '/node')
      ->save(TRUE);

    $this->drupalGet('<front>');

    $assert = $this->assertSession();
    $assert->pageTextContains('Welcome to Drupal');
    $assert->pageTextContains('No front page content has been created yet.');
  }

This test runs really slow against my database … 2+ mins.

If I use a test sqlite database, it drops to around 1.6 mins
<env name="SIMPLETEST_DB" value="sqlite://localhost/logs/test.sqlite"/>

If I use a in-memory database, <env name="SIMPLETEST_DB" value="sqlite://localhost/:memory:"/>, Drupal detects no database and runs install.php

How can I set up an sqlite memory database to improve test speeds?