ZTS: Remove ashift setting from dedup_quota test

The test writes 1M of 1K blocks, which may produce up to 1GB of
dirty data.  On top of that ashift=12 likely produces additional
4GB of ZIO buffers during sync process.  On top of that we likely
need some page cache since the pool reside on files.  And finally
we need to cache the DDT.  Not surprising that the test regularly
ends up in OOMs, possibly depending on TXG size variations.

While here, remove compression.  It has nothing to do here, but
waste CI CPU time.

Signed-off-by:	Alexander Motin <[email protected]>
Sponsored by:	iXsystems, Inc.

Author: amotin

tests/zfs-tests/tests/functional/dedup/dedup_quota.ksh

@@ -79,7 +79,7 @@ function do_setup
 {
 	log_must truncate -s 5G $VDEV_GENERAL
 	# Use 'xattr=sa' to prevent selinux xattrs influencing our accounting
-	log_must zpool create -o ashift=12 -f -O xattr=sa -m $MOUNTDIR $POOL $VDEV_GENERAL
+	log_must zpool create -f -O xattr=sa -m $MOUNTDIR $POOL $VDEV_GENERAL
 	log_must zfs set compression=off dedup=on $POOL
 }
 
@@ -197,7 +197,6 @@ function ddt_dedup_vdev_limit
 	log_must zpool set dedup_table_quota=auto $POOL
 
 	log_must zfs set recordsize=1K $POOL
-	log_must zfs set compression=zstd $POOL
 
 	# Generate a working set to fill up the dedup/special allocation class
 	log_must fio --directory=$MOUNTDIR --name=dedup-filler-1 \