Getting build error for Drupal 11.2.5

Problem / Motivation

When I try to create a simplytest.me instance for Drupal 11.2.5, I get a build error.

Steps:

1. Go to simplytest.me
2. In the field Evaluate Drupal projects, type Drupal
3. Choose Drupal Core from the auto-suggest
4. Accept the default of 11.2.5
5. Click launch sandbox

Expected result: Drupal 11.2.5 installs and launches.

Actual result: I get the following error:

There was a build error

This may be the error:

Your requirements could not be resolved to an installable set of packages.

Problem 1
- Root composer.json requires drupal/core-dev 11.2.5 -> satisfiable by drupal/core-dev[11.2.5].
- drupal/core-dev 11.2.5 requires phpunit/phpunit ^10.5.19 || ^11.5.3 -> satisfiable by phpunit/phpunit[10.5.19, ..., 10.5.x-dev, 11.5.3, ..., 11.5.x-dev].
- phpunit/phpunit[10.3.5, ..., 10.5.26] require sebastian/diff ^5.0 -> found sebastian/diff[5.0.0, ..., 5.1.x-dev] but the package is fixed to 7.0.0 (lock file version) by a partial update and that version does not match. Make sure you list it as an argument for the update command.
- phpunit/phpunit[10.5.27, ..., 10.5.x-dev] require sebastian/diff ^5.1.1 -> found sebastian/diff[5.1.1, 5.1.x-dev] but the package is fixed to 7.0.0 (lock file version) by a partial update and that version does not match. Make sure you list it as an argument for the update command.
- phpunit/phpunit[11.5.3, ..., 11.5.x-dev] require sebastian/diff ^6.0.2 -> found sebastian/diff[6.0.2, 6.0.x-dev] but the package is fixed to 7.0.0 (lock file version) by a partial update and that version does not match. Make sure you list it as an argument for the update command.

Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.

Installation failed, reverting ./composer.json and ./composer.lock to their original content.

Work around is to install the 11.2 development branch, which installs correctly.