As mentioned before: a Spitfire cannot feather its propeller as it doesn’t have a feathering pump. The reason for feathering a prop is improved performance when flying a multi-engined aircraft with one engine out. Especially when this happens right after takeoff, you will then want the best climb rate you can get and getting rid of a windmilling prop is very important!
On a single engined aircraft a feathering option is never incorporated as once the engine fails you will be going down anyway, feathering will only add the option of putting the aircraft in a field that’s 5 miles away, instead of putting it in a field which is 3 miles away. Not much gain for carrying the extra weight around all the time! The odd one out as James mentioned is the Seafire which was recently restored. With six blades windmilling that aircraft will quickly try to imitate a brick once it gets quiet up front, and since the ex-Shack engine already had the mechanics fitted they decided to incorporate the function. Wise decision probably but I’m hoping the pilot doesn’t need to use it!
As James also pointed out many turboprops are started with the blades feathered. The reason behind this is that ideally you want the prop to move to a feathered state on its own once you remove hydraulics/pneumatics/electrics or whatever drives the prop. This is the safest system as feathering pumps, which are only used when badly needed, can also fail! The crash of the Dutch Dakota in 1996(?) was an example of this. Starting with a prop in its feathered state can only be done on a free-turbine engine though as on a direct drive turboprop or a piston engine the drag of the prop in that state is too much to get the engine started!
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