Wrong order of ActionInvoked and NotificationClosed signals emitting

[librolibro]

Output of awesome --version:

awesome v4.3-1606-g0e5fc457-dirty (Too long)
 • Compiled against Lua 5.1.4 (running with LuaJIT 2.1.0-beta3)
 • API level: 4
 • D-Bus support: yes
 • xcb-errors support: no
 • execinfo support: yes
 • xcb-randr version: 1.6
 • LGI version: 0.9.2
 • Transparency enabled: yes
 • Custom search paths: no

How to reproduce the issue:

Note: It will reproduce (at least for me) even with the default config

1. Create notification with one or more actions
2. Open D-Bus monitor to see when exactly ActionInvoked and NotificationClosed signals were emitted
3. Click the action (notification will close after clicking since there's no resident hint)

#!/bin/sh
# Reproducible example
# AFAIK *busctl* is part of the systemd
busctl --user -- call org.freedesktop.Notifications \
    /org/freedesktop/Notifications org.freedesktop.Notifications \
    Notify susssasa{sv}i \
    "" \
    0 \
    "" \
    "Test title" \
    "Test message" \
    "$#" "$@" \
    1 action-icons b true \
    0 && busctl --user --json=short --match="type='signal',interface='org.freedesktop.Notifications'" monitor
# busctl call will print *u MESSAGE_ID* (u is uint32 and MESSAGE_ID is the value)
# busctl monitor will output any call of method for org.freedesktop.Notifications interface in JSON format
#   (for ActionInvoked and NotificationClosed methods the result JSON will contain "payload" dictionary field
#    with "data" list field - first element should be the same MESSAGE_ID)

Actual result:

~ busctl --user -- call org.freedesktop.Notifications \
    /org/freedesktop/Notifications org.freedesktop.Notifications \
    Notify susssasa{sv}i \
    "" \
    0 \
    "" \
    "Test title" \
    "Test message" \
    2 "edit-copy" "Test action" \
    1 action-icons b true \
    0 && busctl --user --json=short --match="type='signal',interface='org.freedesktop.Notifications'" monitor
u 62
Monitoring bus message stream.
{"type":"signal","endian":"l","flags":1,"version":1,"cookie":220,"timestamp-realtime":1691618601401985,"sender":":1.7","path":"/org/freedesktop/Notifications","interface":"org.freedesktop.Notifications","member":"NotificationClosed","payload":{"type":"uu","data":[62,2]}}
{"type":"signal","endian":"l","flags":1,"version":1,"cookie":221,"timestamp-realtime":1691618601402120,"sender":":1.7","path":"/org/freedesktop/Notifications","interface":"org.freedesktop.Notifications","member":"ActionInvoked","payload":{"type":"us","data":[62,"edit-copy"]}}
^C

Expected result:

~ busctl --user -- call org.freedesktop.Notifications \
    /org/freedesktop/Notifications org.freedesktop.Notifications \
    Notify susssasa{sv}i \
    "" \
    0 \
    "" \
    "Test title" \
    "Test message" \
    2 "edit-copy" "Test action" \
    1 action-icons b true \
    0 && busctl --user --json=short --match="type='signal',interface='org.freedesktop.Notifications'" monitor
u 60
Monitoring bus message stream.
{"type":"signal","endian":"l","flags":1,"version":1,"cookie":212,"timestamp-realtime":1691618335769427,"sender":":1.7","path":"/org/freedesktop/Notifications","interface":"org.freedesktop.Notifications","member":"ActionInvoked","payload":{"type":"us","data":[60,"edit-copy"]}}
{"type":"signal","endian":"l","flags":1,"version":1,"cookie":213,"timestamp-realtime":1691618335769487,"sender":":1.7","path":"/org/freedesktop/Notifications","interface":"org.freedesktop.Notifications","member":"NotificationClosed","payload":{"type":"uu","data":[60,2]}}
^C

As you can see, NotificationClosed signal is emitting before the ActionInvoked one - and this happens quite often. I haven't found any source that would confirm that this behavior is acceptable (for example, XDG notification spec contains only method dsecriptions).