Calendar does not respect 24-hour mode without having xdg-desktop-portal-gtk installed

Description:

Although my gnome settings was set to 24-hour mode, gnome calendar would still display all times in am/pm mode. Installing xdg-desktop-portal-gtk fixes this issue.

I suggest adding xdg-desktop-portal-gtk or xdg-desktop-portal-gnome as an (optional?) dependency of gnome-calendar.

Additional info:

The settings in gnome settings where set to 24h mode.

$ gsettings get org.gnome.desktop.interface clock-format
'24h'

However, these settings could not be read by gnome-calendar due to the missing xdg-desktop-portal.

• package version(s): 45.1-1
• config and/or log files: When running G_MESSAGES_DEBUG=all gnome-calendar the output would contain the following:

No such interface “org.freedesktop.portal.Settings” on object at path /org/freedesktop/portal/desktop

• somewhat related upstream issue: https://gitlab.gnome.org/GNOME/gnome-calendar/-/issues/1105

Steps to reproduce:

1. Do not have xdg-desktop-portal-gtk installed.
2. Run gsettings set org.gnome.desktop.interface clock-format '24h'
3. Observe that all times are still displayed in am/pm format.