Dispensers do not equip armor, pumpkins, or player heads onto mobs. Not sure how long this has been an issue. Found out about the issue from my friend streaming his game. Tested in my game as well and sure enough it's an issue. Both in 1.18 and 1.19 releases and he tested.
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We're tracking this issue in MC-190027, so this ticket is being resolved and linked as a duplicate.
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