There seems to be a memory leak in policy_import

It was found by @mrc0mmand in https://github.com/bus1/dbus-broker/pull/359#issuecomment-2061974476 by running dbus-broker under ASan and pointing dfuzzer at it. The backtrace leads to the "ReloadConfig" method.
# TMT_TEST_DATA=~/logs DBUS_BROKER_TREE=$PWD test/integration/fuzz/sanitizers/test.sh
...
[688762.734598] dbus-broker[66]: A security policy denied :1.16 to send method call /org/freedesktop/DBus:org.freedesktop.DBus.Peer.GetMachineId to org.freedesktop.DBus.
[688762.735575] dbus-broker[66]: A security policy denied :1.16 to send method call /org/freedesktop/DBus:org.freedesktop.DBus.Peer.Ping to org.freedesktop.DBus.
[688763.062724] dbus-broker[66]: Dispatched 1954 messages @ 198(±297)μs / message.
[688763.063133] systemd[1]: Stopping D-Bus System Message Bus...
[688763.105139] dbus-broker-launch[65]: =================================================================
[688763.105437] dbus-broker-launch[65]: ==65==ERROR: LeakSanitizer: detected memory leaks
[688763.105437] dbus-broker-launch[65]: Direct leak of 880 byte(s) in 10 object(s) allocated from:
[688763.105564] dbus-broker-launch[65]:     #0 0x75fe014e2cc1 in __interceptor_calloc /usr/src/debug/gcc/gcc/libsanitizer/asan/asan_malloc_linux.cpp:77
[688763.105564] dbus-broker-launch[65]:     #1 0x5b9d8d5fe8f7 in policy_record_new_xmit ../src/launch/policy.c:56
[688763.105564] dbus-broker-launch[65]:     #2 0x5b9d8d609364 in policy_import_send ../src/launch/policy.c:460
[688763.105564] dbus-broker-launch[65]:     #3 0x5b9d8d60f44f in policy_import ../src/launch/policy.c:696
[688763.105564] dbus-broker-launch[65]:     #4 0x5b9d8d5c018b in launcher_load_policy ../src/launch/launcher.c:1096
[688763.105564] dbus-broker-launch[65]:     #5 0x5b9d8d5c1943 in launcher_reload_config ../src/launch/launcher.c:1195
[688763.105564] dbus-broker-launch[65]:     #6 0x5b9d8d5c240c in bus_method_reload_config ../src/launch/launcher.c:1296
[688763.105564] dbus-broker-launch[65]:     #7 0x75fe0131b45c  (/usr/lib/libsystemd.so.0+0x2f45c) (BuildId: 540b0b05a1f8668a797c3ff583cd0b19ff6962f4)
[688763.105564] dbus-broker-launch[65]:     #8 0x75fe01334b1a  (/usr/lib/libsystemd.so.0+0x48b1a) (BuildId: 540b0b05a1f8668a797c3ff583cd0b19ff6962f4)
[688763.105734] dbus-broker-launch[65]: Direct leak of 88 byte(s) in 1 object(s) allocated from:
[688763.105877] dbus-broker-launch[65]:     #0 0x75fe014e2cc1 in __interceptor_calloc /usr/src/debug/gcc/gcc/libsanitizer/asan/asan_malloc_linux.cpp:77
[688763.105877] dbus-broker-launch[65]:     #1 0x5b9d8d5fe8f7 in policy_record_new_xmit ../src/launch/policy.c:56
[688763.105877] dbus-broker-launch[65]:     #2 0x5b9d8d609364 in policy_import_send ../src/launch/policy.c:460
[688763.105877] dbus-broker-launch[65]:     #3 0x5b9d8d60f44f in policy_import ../src/launch/policy.c:696
[688763.105877] dbus-broker-launch[65]:     #4 0x5b9d8d5c018b in launcher_load_policy ../src/launch/launcher.c:1096
[688763.105877] dbus-broker-launch[65]:     #5 0x5b9d8d5c313f in launcher_run ../src/launch/launcher.c:1347
[688763.105877] dbus-broker-launch[65]:     #6 0x5b9d8d5b270c in run ../src/launch/main.c:151
[688763.105877] dbus-broker-launch[65]:     #7 0x5b9d8d5b2949 in main ../src/launch/main.c:174
[688763.105877] dbus-broker-launch[65]:     #8 0x75fe00b1cccf  (/usr/lib/libc.so.6+0x25ccf) (BuildId: c0caa0b7709d3369ee575fcd7d7d0b0fc48733af)
[688763.106017] dbus-broker-launch[65]: SUMMARY: AddressSanitizer: 968 byte(s) leaked in 11 allocation(s).
[688763.115803] systemd[1]: dbus-broker.service: Main process exited, code=exited, status=1/FAILURE
[688763.115956] systemd[1]: dbus-broker.service: Failed with result 'exit-code'.
[688763.116408] systemd[1]: Stopped D-Bus System Message Bus.
[688763.116595] systemd[1]: dbus-broker.service: Consumed 2.112s CPU time, 142.2M memory peak, 0B memory swap peak
bus1 / dbus-broker

There seems to be a memory leak in policy_import #360
