Scribe 2 of 𝓟 initially wrote the singular work; immediately afterwards, he added the plural s inline and then a comma after the s. (Sometimes scribe 2 of 𝓟 added punctuation as he copied from 𝓞 into 𝓟, either a period or a comma or something in-between.) The original manuscript undoubtedly read in the plural. Elsewhere, there are 21 references to “good works” but none to “good work”. In fact, later on in his copywork, scribe 2 of 𝓟 continued to make the same initial error of writing work in place of works:
The example in 3 Nephi 21:5 involves at least one instance, perhaps two, where scribe 2 of 𝓟 miswrote works as work (see the discussion under that passage).
Summary: Maintain in Alma 7:24 scribe 2 of 𝓟’s corrected plural “good works”; the text otherwise refers to “good works”, never to “good work”.