notifications: Notification missing required key during translation: 'str' object has no attribute 'php");print($CONFIG'

While I was re-running some functional tests, I decided to try to dismiss some notifications manually at the same time. Then I noticed this error repeated in the log:

Oct 11 14:56:18 mybox sudo[358695]: pam_unix(sudo:session): session closed for user root
Oct 11 14:56:18 mybox /usr/bin/plinth[724]: Notification missing required key during translation: 'str' object has no attribute 'php");print($CONFIG'
Oct 11 14:56:19 mybox /usr/bin/plinth[724]: # calibre..list_libraries() 
Oct 11 14:56:19 mybox sudo[358793]:   plinth : PWD=/ ; USER=root ; COMMAND=/usr/share/plinth/actions/actions calibre list_libraries --write-fd 25
Oct 11 14:56:19 mybox sudo[358793]: pam_unix(sudo:session): session opened for user root(uid=0) by (uid=110)
Oct 11 14:56:19 mybox sudo[358793]: pam_unix(sudo:session): session closed for user root
Oct 11 14:56:19 mybox /usr/bin/plinth[724]: Notification missing required key during translation: 'str' object has no attribute 'php");print($CONFIG'
Oct 11 14:56:20 mybox /usr/bin/plinth[724]: # users..get_user_groups("tester") 
Oct 11 14:56:20 mybox sudo[358801]:   plinth : PWD=/ ; USER=root ; COMMAND=/usr/share/plinth/actions/actions users get_user_groups --write-fd 22
Oct 11 14:56:20 mybox sudo[358801]: pam_unix(sudo:session): session opened for user root(uid=0) by (uid=110)
Oct 11 14:56:21 mybox sudo[358801]: pam_unix(sudo:session): session closed for user root
Oct 11 14:56:21 mybox /usr/bin/plinth[724]: Notification missing required key during translation: 'str' object has no attribute 'php");print($CONFIG'
Oct 11 14:56:23 mybox /usr/bin/plinth[724]: # plinth..dropin_is_valid("calibre", "/etc/apache2/conf-available/calibre-freedombox.conf", false, unlink_invalid=true) 

The string comes from Nextcloud app here: https://salsa.debian.org/freedombox-team/freedombox/-/blob/main/plinth/modules/nextcloud/privileged.py?ref_type=heads#L399

It seems that notifications is incorrectly trying to format this string, when translating it for display.

The notification text is as follows:

Error installing app: Command '['podman', 'exec', '--user', 'www-data', 'nextcloud-freedombox', 'php', '-r', 'if (file_exists("/var/www/html/config/config.php")) {include_once("/var/www/html/config/config.php");print($CONFIG["dbpassword"] ?? ""); }']' returned non-zero exit status 255.