Drupal Update : Composer failed (your php version does not satisfy that requirement)

Problem

 composer require 'drupal/bootstrap:^3.29'
./composer.json has been updated
Running composer update drupal/bootstrap
Loading composer repositories with package information
Updating dependencies
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - Root composer.json requires drupal/bootstrap ^3.29 -> satisfiable by drupal/bootstrap[3.29.0, 3.x-dev].
    - drupal/bootstrap[3.29.0, ..., 3.x-dev] require php >=8.1.0 -> your php version (7.4; overridden via config.platform, actual: 8.1.21) does not satisfy that requirement.

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.

Lösung : php version entfernen/aktualisieren (in composer.json).