[iOS] Remove unnecessary newline from CI script

A newline was incorrectly added to the script that executes xharness, causing the script to return a 0 exit code even if there was a crash.  This caused CI to report a pass no matter what.  System.IO.Tests was the only suite found where this had an impact.

Contributes to dotnet#67853

eng/testing/tests.ioslike.targets

@@ -25,8 +25,7 @@
     <_AfterBuildCommands>
       mv $XHARNESS_OUT/AOTBuild.binlog &quot;$HELIX_WORKITEM_UPLOAD_ROOT&quot;
       sign &quot;$app&quot;
-      xharness apple test --app &quot;$app&quot; --output-directory &quot;$output_directory&quot; --target &quot;$target&quot; --timeout &quot;$timeout&quot; --xcode &quot;$xcode_path&quot; -v --launch-timeout &quot;$launch_timeout&quot; $(_ResetSimulatorSwitch) $(_SignalAppEndSwitch) -- 
-    </_AfterBuildCommands>
+      xharness apple test --app &quot;$app&quot; --output-directory &quot;$output_directory&quot; --target &quot;$target&quot; --timeout &quot;$timeout&quot; --xcode &quot;$xcode_path&quot; -v --launch-timeout &quot;$launch_timeout&quot; $(_ResetSimulatorSwitch) $(_SignalAppEndSwitch) -- </_AfterBuildCommands>
 
     <RunScriptCommand>$(_AOTBuildCommand) $(_AfterBuildCommands)</RunScriptCommand>
   </PropertyGroup>