[devops] 'simctl diagnose' tend to return an error code, so make sure it doesn't bubble up to the CI. (#18723)

This seems to happen fairly often:

    + xcrun simctl diagnose -b -X --output=/Users/builder/azdo/_work/1/s/diagnostic-sim-output/output
    Error creating archive at '/Users/builder/azdo/_work/1/s/diagnostic-sim-output/output.tar.gz'.
    Files are still in /Users/builder/azdo/_work/1/s/diagnostic-sim-output/output
    An error was encountered processing the command
    (domain=NSPOSIXErrorDomain, code=17):
       Unable to write or file already exists
       File exists

The output directory is empty (created in the line before), so I have no
idea what's going on.

An archive with the diagnostic info still seems to be created though, so
just ignore any failures from 'simctl diagnose' instead of bubbling them up
to Azure DevOps. This makes our test runs not show up with warnings.

tools/devops/automation/templates/tests/run-tests.yml

@@ -175,7 +175,9 @@ steps:
 
     rm -Rf $(System.DefaultWorkingDirectory)/diagnostic-sim-output/output
     mkdir -p $(System.DefaultWorkingDirectory)/diagnostic-sim-output/output
-    printf "\n" | xcrun simctl diagnose -b -X --output=$(System.DefaultWorkingDirectory)/diagnostic-sim-output/output
+    if ! printf "\n" | xcrun simctl diagnose -b -X --output=$(System.DefaultWorkingDirectory)/diagnostic-sim-output/output; then
+      echo "simctl diagnose failed with exit code $?"
+    fi
 
   displayName: 'Collect diagnostic info from simulators'
   condition: eq(variables['system.debug'], true)