CI: run only sanity check on limited OSes for nonbehavioral changes

The commit uses heuristics to determine whether a PR is behavioral:

It runs "quick" CI (i.e., only use sanity.run on fewer OSes)
if (explicitly requested by user):
- the *last* commit message contains a line 'ZFS-CI-Type: quick',
or if (by heuristics):
- the files changed are not in the list of specified directory, and
- all commit messages does not contain 'ZFS-CI-Type: full'.

It runs "full" CI otherwise.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tino Reichardt <milky-zfs@mcmilk.de>
Signed-off-by: Shengqi Chen <harry-chen@outlook.com>
Closes #16564

.github/workflows/scripts/qemu-6-tests.sh

@@ -48,7 +48,7 @@ if [ -z ${1:-} ]; then
   for i in $(seq 1 $VMs); do
     IP="192.168.122.1$i"
     daemonize -c /var/tmp -p vm${i}.pid -o vm${i}log.txt -- \
-      $SSH zfs@$IP $TESTS $OS $i $VMs
+      $SSH zfs@$IP $TESTS $OS $i $VMs $CI_TYPE
     # handly line by line and add info prefix
     stdbuf -oL tail -fq vm${i}log.txt \
       | while read -r line; do prefix "$i" "$line"; done &
@@ -91,6 +91,9 @@ esac
 # run functional testings and save exitcode
 cd /var/tmp
 TAGS=$2/$3
+if [ "$4" == "quick" ]; then
+  export RUNFILES="sanity.run"
+fi
 sudo dmesg -c > dmesg-prerun.txt
 mount > mount.txt
 df -h > df-prerun.txt