main/postmarketos-mkinitfs: trigger on udev changes (MR 5695)

Our regular initramfs imports eudev and its rules, so we need to make
sure that we update the initramfs if they change

[ci:skip-vercheck]: version bump not needed
[ci:skip-build]: already built successfully in CI

main/postmarketos-mkinitfs/APKBUILD

@@ -14,6 +14,7 @@ replaces="mkinitfs"
 triggers="$pkgname.trigger=\
 /lib/firmware/*:\
 /usr/lib/systemd/boot:\
+/usr/lib/udev:\
 /usr/libexec/pmos-tests-initramfs:\
 /usr/share/deviceinfo:\
 /usr/share/kernel/*:\