heap-use-after-free when unmounting external hard drive

Issue Description

I am able to trigger a crash when unmounting an external hard drive via its desktop icon.

Steps to Reproduce Issue

Connect an external hard drive to your computer
Mount the drive by selecting "Mount Volume" in the desktop icon's context menu
Right-click on the icon and select "Unmount Volume" to trigger a use-after-free

Expected Behavior

No crash

Additional Information

It looks like the g_object_unref call on line 73 may be incorrect:

69    } else if (G_IS_FILE_ICON(icon)) {
70        GFile *icon_file = g_file_icon_get_file(G_FILE_ICON(icon));
71        if (icon_file != NULL) {
72            icon_name = g_file_get_path(icon_file);
73            g_object_unref(icon_file);
74        }
75    }

The docs for g_file_icon_get_file say that the return value is owned by the instance.

Backtrace

ERROR: AddressSanitizer: heap-use-after-free on address 0x7baa83198b00 at pc 0x7f7a89d9ef8a bp 0x7ffc3b09ef60 sp 0x7ffc3b09ef58
READ of size 8 at 0x7baa83198b00 thread T0
    #0 0x7f7a89d9ef89 in g_type_check_instance_is_fundamentally_a glib/gobject/gtype.c:3915:41
    #1 0x7f7a89d223ff in g_object_unref glib/gobject/gobject.c:4743:3
    #2 0x7f7a8a583e93 in g_file_icon_finalize glib/gio/gfileicon.c:135:5
    #3 0x7f7a89d22d0e in g_object_unref glib/gobject/gobject.c:4904:3
    #4 0x7b7a7292a468 in g_proxy_mount_update gvfs/monitor/proxy/gproxymount.c:206:5
    #5 0x7b7a7293ad79 in mount_changed gvfs/monitor/proxy/gproxyvolumemonitor.c:555:7

0x7baa83198b00 is located 0 bytes inside of 32-byte region [0x7baa83198b00,0x7baa83198b20)
freed by thread T0 here:
    #0 0x7f7a8ad74a6d  (/usr/lib/clang/21/lib/linux/libclang_rt.asan-x86_64.so+0x174a6d)
    #1 0x7f7a89998048 in g_free_sized glib/glib/gmem.c:238:3
    #2 0x7f7a89d899e2 in g_type_free_instance glib/gobject/gtype.c:1979:5
    #3 0x7f7a89d22de1 in g_object_unref glib/gobject/gobject.c:4920:3
    #4 0x5601181b4961 in icon_name_for_gicon xfdesktop/src/xfdesktop-notify.c:73:13
    #5 0x5601181b4961 in show_notification xfdesktop/src/xfdesktop-notify.c:89:28
    #6 0x5601181b45c0 in xfdesktop_notify_unmount xfdesktop/src/xfdesktop-notify.c:167:18
    #7 0x5601181b17cf in xfdesktop_volume_icon_menu_unmount xfdesktop/src/xfdesktop-volume-icon.c:619:9
[...snip...]

previously allocated by thread T0 here:
    #0 0x7f7a8ad75d6d in calloc
    #1 0x7f7a89997f8a in g_malloc0 glib/glib/gmem.c:133:13
    #2 0x7f7a89d87e40 in g_type_create_instance glib/gobject/gtype.c:1882:17
    #3 0x7f7a89d26825 in g_object_new_internal glib/gobject/gobject.c:2665:24
    #4 0x7f7a89d248db in g_object_new_with_properties glib/gobject/gobject.c:2827:14
    #5 0x7f7a89d248db in g_object_new glib/gobject/gobject.c:2476:12
    #6 0x7f7a8a8b8afc in _g_local_file_new glib/gio/glocalfile.c:236:11
    #7 0x7f7a8a8de789 in g_local_vfs_get_file_for_path glib/gio/glocalvfs.c:88:12
    #8 0x7f7a8a6db854 in g_vfs_get_file_for_path glib/gio/gvfs.c:165:10
    #9 0x7f7a825b516b in g_daemon_vfs_get_file_for_path gvfs/client/gdaemonvfs.c:383:10
    #10 0x7f7a8a6db854 in g_vfs_get_file_for_path glib/gio/gvfs.c:165:10
    #11 0x7f7a8a5680bf in g_file_new_for_path glib/gio/gfile.c:7229:10
    #12 0x7f7a8a5680bf in new_for_cmdline_arg glib/gio/gfile.c:7665:12
    #13 0x7f7a8a56806f in g_file_new_for_commandline_arg glib/gio/gfile.c:7714:10
    #14 0x7f7a8a5aad44 in g_icon_new_for_string_simple glib/gio/gicon.c:413:18
    #15 0x7f7a8a5aa4a3 in g_icon_new_for_string glib/gio/gicon.c:450:10
    #16 0x7b7a7292a60a in g_proxy_mount_update gvfs/monitor/proxy/gproxymount.c:220:19
    #17 0x7b7a7293ad79 in mount_changed gvfs/monitor/proxy/gproxyvolumemonitor.c:555:7
[...snip...]

Environment & Versions

OS distribution and version: Arch Linux
Overall Xfce version: 4.21
xfdesktop version (git hash if not a release): 1628a392
thunar version (if issue related to file/launcher icons): 7f6940ace
Windowing system (X11/Wayland): X11
Compositor and version (if Wayland): N/A
GTK Theme: Adwaita
Icon Theme: elementary
UI Scale Factor: 1x