CI: Test build Lustre against ZFS

The Lustre filessytem calls a number of exported ZFS functions.  Do a
test build on the Almalinux runners to make sure we're not breaking
Lustre.  We do the Lustre build in parallel with the normal ZTS test
for efficiency, since ZTS isn't very CPU intensive. The full Lustre
build takes around 15min when run on its own.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes #18161

.github/workflows/scripts/qemu-8-summary.sh

@@ -31,6 +31,12 @@ EOF
   rm -f tmp$$
 }
 
+function showfile_tail() {
+  echo "##[group]$2 (final lines)"
+  tail -n 40 $1
+  echo "##[endgroup]"
+}
+
 # overview
 cat /tmp/summary.txt
 echo ""
@@ -46,6 +52,20 @@ fi
 echo -e "\nFull logs for download:\n    $1\n"
 
 for ((i=1; i<=VMs; i++)); do
+
+  # Print Lustre build test results (the build is only done on vm2)
+  if [ -f vm$i/lustre-exitcode.txt ] ; then
+    rv=$(< vm$i/lustre-exitcode.txt)
+    if [ $rv = 0 ]; then
+      vm="vm$i"
+    else
+      vm="vm$i"
+      touch /tmp/have_failed_tests
+    fi
+    file="vm$i/lustre.txt"
+    test -s "$file" && showfile_tail "$file" "$vm: Lustre build"
+  fi
+
   rv=$(cat vm$i/tests-exitcode.txt)
 
   if [ $rv = 0 ]; then