Display the crash tests stdout live (#5964)

## Summary of changes

In the crashtracking installer smoke-tests, display the output as it
comes instead of all at once when it finishes.

## Reason for change

The job sometimes hangs. When it happens, it gets killed after the
timeout elapses, and we see no output because the command didn't
complete.

## Implementation details

Bash.

.azure-pipelines/steps/run-snapshot-test.yml

@@ -146,8 +146,12 @@ steps:
 # Run crash tests
 - ${{ if and(eq(parameters.isLinux, true), eq(parameters.isNoop, false)) }}:
   - bash: |
-      LOGS=$(${{ parameters.dockerComposePath }} -f $(COMPOSE_PATH) -p ddtrace_$(Build.BuildNumber) run -e dockerTag=$(dockerTag) -e CRASH_APP_ON_STARTUP=1 -e COMPlus_DbgEnableMiniDump=0 ${{ parameters.target }})
-      echo $LOGS
+      LOGS=""
+      while IFS= read -r line
+      do
+        echo "$line"  # Output the log line to stdout in real-time
+        LOGS+="$line"$'\n'  # Capture each line into LOGS variable
+      done < <(${{ parameters.dockerComposePath }} -f $(COMPOSE_PATH) -p ddtrace_$(Build.BuildNumber) run -e dockerTag=$(dockerTag) -e CRASH_APP_ON_STARTUP=1 -e COMPlus_DbgEnableMiniDump=0 ${{ parameters.target }})
 
       # check logs for evidence of crash detection in the output
       expected="The crash may have been caused by automatic instrumentation"