bump required version

I'm getting an error when I tried to run the latest version using a Profile - specifically:

Trying to access array offset on value of type null in Civi\Formprotection\Recaptcha->shouldAddCaptchaToForm() (line 338 of /var/www/powerbase/sites/all/extensions/formprotection/Civi/Formprotection/Recaptcha.php).

I'm pretty sure it's because I'm running 5.51 which doesn't have this commit.