Update stripe library to v9

composer.json

composer.lock

vendor/composer/InstalledVersions.php

vendor/composer/installed.json

vendor/composer/installed.php

vendor/stripe/stripe-php/.coveralls.github-actions.yml

vendor/stripe/stripe-php/.php-cs-fixer.php

vendor/stripe/stripe-php/CHANGELOG.md

vendor/stripe/stripe-php/Makefile

vendor/stripe/stripe-php/OPENAPI_VERSION

vendor/stripe/stripe-php/README.md

vendor/stripe/stripe-php/VERSION

vendor/stripe/stripe-php/composer.json

vendor/stripe/stripe-php/data/ca-certificates.crt

vendor/stripe/stripe-php/init.php

vendor/stripe/stripe-php/lib/Account.php

...stripe/stripe-php/lib/ApiOperations/SingletonRetrieve.php

vendor/stripe/stripe-php/lib/ApiRequestor.php

vendor/stripe/stripe-php/lib/Apps/Secret.php

vendor/stripe/stripe-php/lib/Balance.php