Remove use of DDC during CI tests (#3367)

# Description of Changes

Removes the use of the Derived Data Cache during CI, will in

# API and ABI breaking changes

None

# Expected complexity level and risk

1 - Small change for CI

# Testing

- [x] Re-ran tests on both Linux + Windows with the change

Author: JasonAtClockwork

sdks/unreal/tests/TestClient/Config/DefaultEngine.ini

@@ -1,4 +1,10 @@
+[Zen]
+bEnableZen=false
+bEnableZenLocal=false
 
+[/Script/Zen.ZenServiceSettings]
+bEnabled=False
+bAutoLaunch=False
 
 [Audio]
 UseAudioMixer=True

sdks/unreal/tests/test.rs

@@ -83,7 +83,10 @@ fn make_test(test_name: &str) -> Test {
     // Run automation test
 
     let run_command = format!(
-        "\"{editor_exe}\" \"{uproject_path}\" -NullRHI -Unattended -NoSound -nop4 -NoSplash -DDC-ForceMemoryCache -ddc=InstalledNoZenLocalFallback -ExecCmds=\"Automation RunTests SpacetimeDB.TestClient.{test_name}; Quit\""
+		// Updated to -NoZen and -dcc=InstalledNoZenLocalFallback to stop Unreal from trying to install Zen Server in CI
+		// This is failing during tests as each test tries to install Zen and create a race condition where two tests try to handle this at the same time
+		// Zen Server and the Derived Cache seem like a good idea during tests but they were not designed with mutli-threaded tests in mind, it is suggested to allow each test to run in isolation
+        "\"{editor_exe}\" \"{uproject_path}\" -NullRHI -Unattended -NoSound -nop4 -NoSplash -NoZen -ddc=InstalledNoZenLocalFallback -ExecCmds=\"Automation RunTests SpacetimeDB.TestClient.{test_name}; Quit\""
     );
 
     Test::builder()