api: union undefined

Set the option to generate union undefined types for objects that have
optional items. This will allow us to enable `exactOptionalPropertyTypes`
in our tsconfig [1].

[1] This is a recommended setting, see:
https://www.typescriptlang.org/tsconfig/#exactOptionalPropertyTypes

src/store/wizardSlice.ts

@@ -56,7 +56,7 @@ export type wizardState = {
     accountId: string;
     shareMethod: AwsShareMethod;
     source: V1ListSourceResponseItem | undefined;
-    sourceId?: string;
+    sourceId?: string | undefined;
   };
   azure: {
     shareMethod: AzureShareMethod;