Technically, it is a homonym. Homonyms are separated into two categories, homophones (sound the same but spelled differently, such as they’re/their/there) and homographs, which are spelled the same but have different meanings, such as lead (the metal) and lead (the verb).
Led is the past tense of the verb “to lead”.
Led is a homophone of lead (the metal) whereas lead is a homograph of lead (again, the metal).