clear errors in success pathway (#40672) (#40732)

if a previous run had an error, it will remain present but the state
would be "indexed". We should just clear that error.

Co-authored-by: dpsutton <dan@dpsutton.com>

src/metabase/models/model_index.clj

@@ -135,6 +135,7 @@ don't, (and shouldn't) care that those are expressions. They are just another fi
                                  additions-part)))))
           (t2/update! ModelIndex (:id model-index)
                       {:indexed_at :%now
+                       :error      nil
                        :state      (if (> (count values-to-index) max-indexed-values)
                                      "overflow"
                                      "indexed")}))