NetBSD 11: / has EAs enabled, use a TMPDIR there

/tmp is a tmpfs without EAs, we can't use that for our tests. On
NetBSD 11 the root filesystem has extended attributes enabled, so a
plain directory there works and we do not need to build, attach and
mount a separate FFS image anymore.

Co-Authored-By: Claude Opus 5 <[email protected]>

.github/workflows/ci.yml

@@ -394,18 +394,9 @@ jobs:
               sudo -E ln -sf /usr/pkg/bin/tox-3.11 /usr/pkg/bin/tox3
               # Ensure base system admin tools are on PATH for the non-root shell
               export PATH="/sbin:/usr/sbin:$PATH"
-              echo "--- Preparing an extattr-enabled filesystem ---"
-              # On many NetBSD setups /tmp is tmpfs without extended attributes.
-              # Create a FFS image with extended attributes enabled and use it for TMPDIR.
-              VNDDEV="vnd0"
-              IMGFILE="/tmp/fs.img"
-              sudo -E dd if=/dev/zero of=${IMGFILE} bs=1m count=1024
-              sudo -E vndconfig -c "${VNDDEV}" "${IMGFILE}"
-              sudo -E newfs -O 2ea /dev/r${VNDDEV}a
-              MNT="/mnt/eafs"
-              sudo -E mkdir -p ${MNT}
-              sudo -E mount -t ffs -o extattr /dev/${VNDDEV}a $MNT
-              export TMPDIR="${MNT}/tmp"
+              # On the netbsd 11 VM, / is a fs with extended attributes,
+              # while /tmp is a tmpfs without them - so don't use /tmp.
+              export TMPDIR="/tmp_eafs"
               sudo -E mkdir -p ${TMPDIR}
               sudo -E chmod 1777 ${TMPDIR}
               touch ${TMPDIR}/testfile