[BUG] The icon of "Preferences" menu is shown as a broken image

[ryonakano]

Describe the bug
The icon of "Edit" → "Preferences" menu is not shown and the broken image icon is shown instead.

To Reproduce

1. Launch FSearch
2. Open "Edit" → "Preferences" in the menu bar
3. See the icon of "Preferences" menu item is shown as the broken image icon

Expected behavior
The icon of "Preferences" menu item should be an appropriate icon instead of the broken image icon.

Screenshots

Desktop (please complete the following information):

• OS: [e.g. Ubuntu 20.04]: Fedora 40 (GNOME 46)
• How you installed FSearch [e.g. built manually, PPA, AUR]: built manually (rev: 8cdfff4)
• Version [output of fsearch --version]: FSearch 0.3.alpha0
• Output of localectl status

user@fedora:~/work/fsearch$ localectl status
System Locale: LANG=ja_JP.UTF-8
    VC Keymap: jp
   X11 Layout: jp
    X11 Model: pc105
user@fedora:~/work/fsearch$ 

Additional context
I think this is because there is no such icon named preferences-desktop both in the system and in the source of FSearch which is specified here:

fsearch/src/menus.ui

Line 87 in 8cdfff4

<attribute name="icon">preferences-desktop</attribute>

user@fedora:~/work/fsearch$ find /usr/share/icons/ -name "preferences-desktop*"
/usr/share/icons/Adwaita/symbolic/legacy/preferences-desktop-accessibility-symbolic.svg
/usr/share/icons/Adwaita/symbolic/legacy/preferences-desktop-appearance-symbolic.svg
/usr/share/icons/Adwaita/symbolic/legacy/preferences-desktop-apps-symbolic.svg
/usr/share/icons/Adwaita/symbolic/legacy/preferences-desktop-display-symbolic.svg
/usr/share/icons/Adwaita/symbolic/legacy/preferences-desktop-font-symbolic.svg
/usr/share/icons/Adwaita/symbolic/legacy/preferences-desktop-keyboard-shortcuts-symbolic.svg
/usr/share/icons/Adwaita/symbolic/legacy/preferences-desktop-keyboard-symbolic.svg
/usr/share/icons/Adwaita/symbolic/legacy/preferences-desktop-locale-symbolic.svg
/usr/share/icons/Adwaita/symbolic/legacy/preferences-desktop-multitasking-symbolic.svg
/usr/share/icons/Adwaita/symbolic/legacy/preferences-desktop-remote-desktop-symbolic.svg
/usr/share/icons/Adwaita/symbolic/legacy/preferences-desktop-screensaver-symbolic.svg
/usr/share/icons/Adwaita/symbolic/legacy/preferences-desktop-wallpaper-symbolic.svg
user@fedora:~/work/fsearch$ git grep -nw preferences-desktop
src/menus.ui:87:                    <attribute name="icon">preferences-desktop</attribute>
user@fedora:~/work/fsearch$