Magento 2 Upgrade & QA

My store is currently on Magento 2.4.6 and I need it moved to the latest Magento 2 release. The job is not just a straight-forward core update; I also expect a full round of post-upgrade testing and any fixes required to keep daily sales flowing smoothly... (Budget: £1000 - £1800 GBP, Jobs: HTML, JavaScript, Magento, Magento 2, PHP, Web Design, Web Development, Website Testing)