Report backend version in CI runner script

Author: ianfixes

Diff for: exe/arduino_ci.rb

@@ -559,6 +559,7 @@ def perform_example_compilation_tests(cpp_library, config)
 
 @backend = ArduinoCI::ArduinoInstallation.autolocate!
 inform("Located arduino-cli binary") { @backend.binary_path.to_s }
+inform("Using arduino-cli version") { @backend.version.to_s }
 if @backend.lib_dir.exist?
   inform("Found libraries directory") { @backend.lib_dir }
 else