Type error with exactOptionalPropertyTypes on#63

### Describe the bug Given this code: `const booleanFilters = queryParam('bf', ssp.array<string>([]));` I get this typescript error when `exactOptionalPropertyTypes` is true in my tsconfig ``` Argument of type '{ encode: (value: string[]) => string; decode: (value: string | null) => string[] | null; defaultValue: string[] | undefined; }' is not assignable to parameter of type 'EncodeAndDecodeOptions<string[]>' with 'exactOptionalPropertyTypes: true'. Consider adding 'undefined' to the types of the target's properties. Types of property 'defaultValue' are incompatible. Type 'string[] | undefined' is not assignable to type 'string[]'. Type 'undefined' is not assignable to type 'string[]'.ts(2379) ``` ### Reproduction import { ssp, queryParam } from 'sveltekit-search-params'; const booleanFilters = queryParam('bf', ssp.array<string>([])); ### Logs _No response_