chore(examples): use api.Ptr for optional pointer fields

Replace the throwaway-local-var-then-take-address pattern with
api.Ptr in the polls and moderation examples. Net effect: 14 lines
gone, the pointer wrangling no longer steals visual focus from the
actual API call.

examples/polls/main.go

@@ -94,12 +94,11 @@ func main() {
 			})
 			return nil
 		}
-		isAnon := false
 		msg, err := api.SendPoll(c.Ctx, c.Bot, &api.SendPollParams{
 			ChatID:      api.ChatIDFromInt(m.Chat.ID),
 			Question:    question,
 			Options:     pollOptions,
-			IsAnonymous: &isAnon,
+			IsAnonymous: api.Ptr(false),
 		})
 		if err != nil {
 			return err