Remove obsolete PoolManager methods (#19499)

Content.IntegrationTests/Tests/HumanInventoryUniformSlotsTest.cs

@@ -58,7 +58,7 @@ namespace Content.IntegrationTests.Tests
         {
             await using var pair = await PoolManager.GetServerClient();
             var server = pair.Server;
-            var testMap = await PoolManager.CreateTestMap(pair);
+            var testMap = await pair.CreateTestMap();
             var coordinates = testMap.GridCoords;
 
             EntityUid human = default;