build: ensure check.sh fails if *any* requested check fails

The current logic, which is bugged, is:

  if at least one health check succeeded, check.sh succeeds.
  otherwise, check.sh fails.

This is bugged because it allows CI to pass even if all
healthchecks except for one failed.

We change the logic to instead be:

  if no checks ran at all OR if at least one check failed, check.sh fails.
  otherwise, check.sh suceeds.

Author: kdmccormick

check.sh

@@ -123,7 +123,10 @@ fi
 
 echo "Successful checks:${succeeded:- NONE}"
 echo "Failed checks:${failed:- NONE}"
-if [[ "$succeeded" ]]; then
+if [[ -z "$succeeded" ]] && [[ -z "$failed" ]]; then
+    echo "No checks ran. Exiting as failure."
+    exit 1
+elif [[ -z "$failed" ]]; then
     echo "Check result: SUCCESS"
     exit 0
 else