modemmanager: bump to 1.18.4 with patch

modemmanager: bump to 1.18.4 with patch

The included patch corrects an issue preventing udev rules from
being parsed correctly. [1][2]

This patch should not be needed after the next release. [3]

More information:
[1] https://gitlab.freedesktop.org/mobile-broadband/ModemManager/-/commit/e9f254ba3f923248efffe4fd458dc5e5469e0f73
[2] https://lists.freedesktop.org/archives/modemmanager-devel/2021-December/009024.html
[3] https://lists.freedesktop.org/archives/modemmanager-devel/2021-December/009022.html

Signed-off-by: Nicholas Smith <nicholas@nbembedded.com>