fix(medusa): ShippingOptionService.list method param type (#4018)

## What

Fix typing on ShippingOptionService.list selector parameter

## Why

A backend server interfacing with the `ShippingOptionService.list()` method will throw TS error when attempting to pass selector values that should be valid.

## Steps to reproduce

* In a IDE that can display TS errors
* Create an instance of the ShippingOptionService
* Call the `list()` method on the instance with the following selector parameter: `{ region_id: "foobar" }`
* Expect: No TS error
* Actual: `TS2345: Argument of type '{ region_id: string; }' is not assignable to parameter of type 'Selector<ShippingMethod>'.`

## How

* Change the `selector` type to `Selector<ShippingOption>`

.changeset/good-beans-know.md

@@ -0,0 +1,5 @@
+---
+"@medusajs/medusa": patch
+---
+
+fix(medusa): ShippingOptionService.list method param type

packages/medusa/src/services/shipping-option.ts

@@ -143,7 +143,7 @@ class ShippingOptionService extends TransactionBaseService {
    * @return {Promise} the result of the find operation
    */
   async list(
-    selector: Selector<ShippingMethod>,
+    selector: Selector<ShippingOption>,
     config: FindConfig<ShippingOption> = { skip: 0, take: 50 }
   ): Promise<ShippingOption[]> {
     const optRepo = this.activeManager_.withRepository(this.optionRepository_)