Notwithstanding any other provision of this Code, any diploma conferred during the 2019-2020 school year, including during the summer of 2020, under graduation requirements that were modified by an executive order, emergency rulemaking, or school board policy prompted by a gubernatorial disaster proclamation as a result of COVID-19 is deemed valid and is not subject to challenge or review due to a failure to meet minimum requirements otherwise required by this Code, administrative rule, or school board policy.