vinyl: move vinyl/write_iterator_rand to --long tests

test/vinyl/suite.ini

@@ -2,10 +2,10 @@
 core = tarantool
 description = vinyl integration tests
 script = vinyl.lua
-disabled = split.test.lua write_iterator_rand.test.lua
+disabled = split.test.lua
 valgrind_disabled =
 release_disabled = errinj.test.lua recover.test.lua
 config = suite.cfg
 lua_libs = suite.lua stress.lua large.lua txn_proxy.lua ../box/lua/utils.lua
 use_unix_sockets = True
-long_run = stress.test.lua large.test.lua
+long_run = stress.test.lua large.test.lua write_iterator_rand.test.lua