Remove flaky remove-collection-color-test (#35847)

test/metabase/db/schema_migrations_test.clj

@@ -551,11 +551,7 @@
 
         (migrate!)
         (testing "should drop the existing color column"
-          (is (not (contains? (t2/select-one :model/Collection :id collection-id) :color))))
-
-        (migrate! :down 47)
-        (testing "Rollback to the previous version should restore the column column, and set the default color value"
-          (is (= "#31698A" (:color (t2/select-one :model/Collection :id collection-id)))))))))
+          (is (not (contains? (t2/select-one :model/Collection :id collection-id) :color))))))))
 
 (deftest audit-v2-views-test
   (testing "Migrations v48.00-029 - v48.00-040"