test(service): fix E0283 in list_games mock tests to unbreak Backend CI

[abdulwaarith0]

Summary

cargo test for the service module currently fails to compile, turning Backend CI red on main and on every open PR. The error:

error[E0283]: type annotations needed
  --> modules/service/src/games.rs:616 and :678
     .append_query_results(vec![ vec![] ])
      ^^^^^^^^^^^^^^^^^^^^^ cannot infer type of the type parameter `T`
                                 declared on the method `append_query_results`

Root cause

In test_list_games_query_structure and test_list_games_with_cursor, the count query's mock result set is an untyped empty vec![]. Under sea-orm 1.1.20 the additional IntoMockRow impls make the element type of an empty vec ambiguous, so append_query_results::<T, _, _> can no longer infer T. (Introduced when the count query result set was added in the pagination work — the data-query set compiles fine because game::Model pins its type.)

Fix

Type the empty count set as Vec::<game::Model>::new() so T: IntoMockRow is inferable. No behavior change — count() on an empty mock result resolves to 0 and execution continues to the data query, so both queries still run and transaction_log.len() == 2 still holds.

Verification

Built in isolation against sea-orm 1.1.20 (the workspace can't build the full service crate locally due to an unrelated OpenSSL dev-dep). A minimal entity reproducing the exact flow confirms:

count on empty mock = 0
data rows           = 1
transaction_log.len() = 2

i.e. the typed empty set compiles, count() returns 0 without error, and both the count and data queries execute — matching each test's assertions.