(EDITED:) If the Outlet is only and “permanently” used for a dumb Bulb (connected to a dumb Outlet), then just replace the switch with a dimmable smart switch. That is the simplest and most direct solution.
Every alternative means you need to have some indirect connection from the switch to the bulb (possibly a smart dimmable outlet and/or bulb + a smart switch…). In this case, the typical and correct solution is to actually disconnect the switch from the circuit … it becomes a “remote control” only and just powered by the mains available at the switch if there is a neutral wire at the switch. (There is no good way to 100% reliably link the smart switch and smart outlet/bulb … But we do it anyway via SmartThings and/or possibly Z-Wave Direct Association, and it can work “ok”.) If there is no neutral at the switch, then there are some battery powered options, but not great ones. There’s a Topic you can search for.
The first option is not available to all folks; what if there is no Neutral wire at the switch?; what if the outlet is used for more than light?; what if you want physical control closer to the light?