test: use /run/ for test configuration, not /etc/

In case of failures we don't want to leave an image with intermediate
test configuration, as images are reused across multiple tests

Follow-up for edca63a

Author: bluca

test/units/TEST-07-PID1.concurrency.sh

@@ -9,42 +9,42 @@ set -o pipefail
 # shellcheck source=test/units/util.sh
 . "$(dirname "$0")"/util.sh
 
-cat >/etc/systemd/system/concurrency1.slice <<EOF
+cat >/run/systemd/system/concurrency1.slice <<EOF
 [Slice]
 ConcurrencyHardMax=4
 ConcurrencySoftMax=3
 EOF
 
-cat >/etc/systemd/system/[email protected] <<EOF
+cat >/run/systemd/system/[email protected] <<EOF
 [Service]
 Slice=concurrency1.slice
 ExecStart=sleep infinity
 EOF
 
-cat >/etc/systemd/system/[email protected] <<EOF
+cat >/run/systemd/system/[email protected] <<EOF
 [Unit]
 After=sleepforever1@%i.service
 
 [Service]
 ExecStart=true
 EOF
 
-cat >/etc/systemd/system/concurrency1-concurrency2.slice <<EOF
+cat >/run/systemd/system/concurrency1-concurrency2.slice <<EOF
 [Slice]
 ConcurrencySoftMax=1
 EOF
 
-cat >/etc/systemd/system/[email protected] <<EOF
+cat >/run/systemd/system/[email protected] <<EOF
 [Service]
 Slice=concurrency1-concurrency2.slice
 ExecStart=sleep infinity
 EOF
-cat >/etc/systemd/system/concurrency1-concurrency3.slice <<EOF
+cat >/run/systemd/system/concurrency1-concurrency3.slice <<EOF
 [Slice]
 ConcurrencySoftMax=1
 EOF
 
-cat >/etc/systemd/system/[email protected] <<EOF
+cat >/run/systemd/system/[email protected] <<EOF
 [Service]
 Slice=concurrency1-concurrency3.slice
 ExecStart=sleep infinity
@@ -117,12 +117,12 @@ systemctl start [email protected]
 systemctl stop concurrency1.slice
 systemctl reset-failed
 
-rm /etc/systemd/system/concurrency1.slice
-rm /etc/systemd/system/concurrency1-concurrency2.slice
-rm /etc/systemd/system/concurrency1-concurrency3.slice
-rm /etc/systemd/system/[email protected]
-rm /etc/systemd/system/[email protected]
-rm /etc/systemd/system/[email protected]
-rm /etc/systemd/system/[email protected]
+rm /run/systemd/system/concurrency1.slice
+rm /run/systemd/system/concurrency1-concurrency2.slice
+rm /run/systemd/system/concurrency1-concurrency3.slice
+rm /run/systemd/system/[email protected]
+rm /run/systemd/system/[email protected]
+rm /run/systemd/system/[email protected]
+rm /run/systemd/system/[email protected]
 
 systemctl daemon-reload