There are some spec upgrades for peripherals connectivity, though (Thunderbolt, Wifi, external monitors), if that matters to you. And the M4 Macbook Pro finally has that etched anti-glare screen if you ever want to use it outdoors.
Otherwise, the M1 is still a very capable machine and miles better than the PC laptops we all grew up with. Does anything in your day to day work actually feel slow? If so, maybe you can benchmark it and see if the upgrade would actually help much. If it's single-threaded work, especially, there may not be a big upgrade. If your workload is heavily multi-threaded or GPU heavy and you're on the base M1, the M4 Pro or Max could be a big upgrade, but most coding work probably isn't.