Fix error when setting license key from command line #19118

Description:

Attempting to set a plugin license key with ./console marketplace:set-license-key --license-key="xxx" results in the error

Uncaught exception: Error: Class "Piwik\Plugins\Marketplace\Api" not found in 
/var/www/matomo/plugins/Marketplace/Commands/SetLicenseKey.php:39

(Debian 11 running PHP 8.1.1)

This error appears to be caused by case sensitivity on the referenced class name, where the class name is API but the the referenced class is Api which is not PSR-4 compliant. Changing the referenced class name to API fixes the error.

Ref L3-258

Review

• [ ] Functional review done
• [ ] Potential edge cases thought about (behavior of the code with strange input, with strange internal state or possible interactions with other Matomo subsystems)
• [ ] Usability review done (is anything maybe unclear or think about anything that would cause people to reach out to support)
• [ ] Security review done
• [ ] Wording review done
• [ ] Code review done
• [ ] Tests were added if useful/possible
• [ ] Reviewed for breaking changes
• [ ] Developer changelog updated if needed
• [ ] Documentation added if needed
• [ ] Existing documentation updated if needed

This is an error we actually might be able to prevent with phpcs. Might be useful to evaluate that maybe.