tests: clean out unused/single-use/useless commands from the list

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #13259

tests/zfs-tests/include/commands.cfg

@@ -8,9 +8,7 @@
 # Please keep the contents of each variable sorted for ease of reading
 # and maintenance.
 #
-export SYSTEM_FILES_COMMON='arp
-    awk
-    base64
+export SYSTEM_FILES_COMMON='awk
     basename
     bc
     bunzip2
@@ -52,10 +50,10 @@ export SYSTEM_FILES_COMMON='arp
     ksh
     ldd
     ln
-    logname
     ls
     mkdir
     mknod
+    mkfifo
     mktemp
     mount
     mv
@@ -67,12 +65,9 @@ export SYSTEM_FILES_COMMON='arp
     pgrep
     ping
     pkill
-    printenv
     printf
     ps
-    pwd
     python3
-    quotaon
     readlink
     rm
     rmdir
@@ -88,32 +83,26 @@ export SYSTEM_FILES_COMMON='arp
     ssh
     stat
     strings
-    su
     sudo
     swapoff
     swapon
     sync
     tail
     tar
-    tee
     timeout
     touch
     tr
     true
     truncate
-    umask
     umount
     uname
     uniq
-    uuidgen
     vmstat
-    wait
     wc'
 
 export SYSTEM_FILES_FREEBSD='chflags
     compress
     diskinfo
-    dumpon
     fsck
     getextattr
     gpart
@@ -123,7 +112,6 @@ export SYSTEM_FILES_FREEBSD='chflags
     lsextattr
     md5
     mdconfig
-    mkfifo
     newfs
     pw
     rmextattr
@@ -135,14 +123,11 @@ export SYSTEM_FILES_FREEBSD='chflags
     uncompress'
 
 export SYSTEM_FILES_LINUX='attr
-    bash
     blkid
     blockdev
     chattr
-    dmidecode
     exportfs
     fallocate
-    fdisk
     free
     getfattr
     groupadd
@@ -159,16 +144,17 @@ export SYSTEM_FILES_LINUX='attr
     mkswap
     modprobe
     mpstat
-    nproc
     parted
     perf
-    setenforce
     setfattr
     sha256sum
     udevadm
     useradd
     userdel
-    usermod'
+    usermod
+
+    flock
+    logger'
 
 export ZFS_FILES='zdb
     zfs