Remove Devin Lifeguard. Improve Arduino cache disk space issue.

Author: dgarske

.github/workflows/arduino.yml

@@ -82,6 +82,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
+        max-parallel: 2
         fqbn:
           # When editing this list, be sure to also edit file: board_list.txt
           #   The compile-all-examples.sh optionally takes a FQBN parameter to