Make spectator markers a constant

Data/Scripts/Miscellaneous/GameManager/SkirmishGameClass.lua

@@ -24,9 +24,15 @@ function SkirmishGameClass:New(gameMode)
     local function FindSpectators()
         ---@type SpectatorStruct[]
         local spectators = {}
-        local spectatorMarker = GetSpectatorMarkerName(gameMode)
+        local spectatorMarker = nil
 
-        if spectatorMarker ~= nil then
+        if StringCompare(gameMode, "Space") then
+            spectatorMarker = Spectator_Marker_Space
+        elseif StringCompare(gameMode, "Land") then
+            spectatorMarker = Spectator_Marker_Land
+        end
+
+        if spectatorMarker then
             for k, marker in pairs(Find_All_Objects_Of_Type(spectatorMarker)) do
                 local playerWrapper = marker.Get_Owner()
                 local playerId = playerWrapper.Get_ID()