The original text here has the archaic simple past-tense form forgat rather than the modern forgot. Both manuscripts originally read forgat, although Oliver Cowdery initially wrote forget in 𝓞 but then virtually immediately corrected it to forgat by overwriting the e with an a (there is no change in the level of ink flow for the overwriting). Oliver wrote forgat in 𝓟, but the 1830 compositor set the modern form forgot. When Joseph Smith grammatically edited 𝓟 for the 1837 edition, he emended the forgat in 𝓟 to forgot.
The archaic forgat is also found later in the book of Alma, where it serves three times as the past participle for the verb forget:
Note here that the 1830 compositor consistently replaced forgat with forgot. The 1906 LDS edition made the change from forgot to forgotten, the standard past participial form. The original Book of Mormon text frequently used simple past-tense verb forms for the past participle. For discussion, see under past participle in volume 3. Here forgat parallels the archaic past-tense form gat for the verb get; both forms, forgat and gat, are found in the original Book of Mormon text. For discussion of gat, see under Alma 10:32. Also see the discussion under past tense for other instances of nonstandard past-tense forms in the original Book of Mormon text.
The earliest text of the Book of Mormon has only one occurrence of the simple past-tense form for forget and it reads forgat (here in Alma 37:41). As far as the past participle is concerned, there are eleven occurrences of forgotten and three of the nonstandard forgat in the earliest text (all three are in Alma 60:20, listed above). These results are in part similar to what we find in the King James Bible: forgat is consistently the simple past-tense form for the verb forget (eight times), never forgot; for the past participle, the King James translation has 46 occurrences of the standard forgotten but one of forgot (in Deuteronomy 24:19). For each form of the verb forget, the critical text will follow the earliest reading, thus forgat as the simple past-tense form here in Alma 37:41 and as the past participle three times in Alma 60:20 (otherwise, forgotten is the past participial form).
Summary: In accord with the original reading in the manuscripts, restore in Alma 37:41 the archaic forgat as the simple past-tense form; also restore the same form, but as the past participle, three times in Alma 60:20.