fix: Apollo Client cache merge causing product duplication

The merge function was concatenating products on each query, causing
4 products to become 8, then 12, etc. Changed to replace incoming
data instead of merging.

src/lib/saleor/client.ts

@@ -24,12 +24,8 @@ export const saleorClient = new ApolloClient({
         fields: {
           products: {
             keyArgs: ["channel", "filter"],
-            merge(existing, incoming) {
-              if (!existing) return incoming;
-              return {
-                ...incoming,
-                edges: [...existing.edges, ...incoming.edges],
-              };
+            merge(_existing, incoming) {
+              return incoming;
             },
           },
         },