Many traditional specialty contractors are exempt from Georgia's contractor licensing rules. According to this resource from the Georgia Secretary of State, many drywall contractors will be exempt and won't need to obtain a license: List of Exempt Traditional Specialty Contractors. So, if a contractor is merely providing drywall work, then a license may not be required.
With that being said, I'd hardly claim to be a licensing expert. And, browsing the Georgia Secretary of State site or contacting them directly might be useful. Additionally, reaching out to a local Georgia construction attorney or to some other licensing consultant could be helpful, too.