Allow execute on mount to be empty object when input is undefined

[DavidRowthorn]

For an action that doesn't take any input, the following produces a type error (using WebStorm), complaining about input not being a required field.

const { result } = useAction(myAction, {
    executeOnMount: {},
  })

The following fixes it:

const { result } = useAction(myAction, {
    executeOnMount: { input: undefined },
  })

{ input: undefined } should be treated as equivalent to {}.

[TheEdoRan]

Fixed in v7.6.2