Avoid duplicate checks for password change

[GhaziTriki]

Password checks are already done in the execute function. Double checks in changePassword are obselete and dead code.

https://github.com/riadvice/bbbeasy/blob/93bf0f553d40b8e49c9bf873078dd22bd11a308e/bbbeasy-backend/app/src/Actions/Account/ChangePassword.php#LL95C22-L95C36