fix: Avoid fcitx5 override of xcb keyboard layout (#760)

* fix: Avoid fcitx5 override of xcb keyboard layout

* Clean up migration

* Comment says what the command says

---------

Co-authored-by: David Heinemeier Hansson <david@hey.com>

config/fcitx5/conf/xcb.conf

@@ -0,0 +1 @@
+Allow Overriding System XKB Settings=False

migrations/1755139080.sh

@@ -0,0 +1,9 @@
+echo "Ensure fcitx5 does not overwrite xkb layout"
+
+FCITX5_CONF_DIR="$HOME/.config/fcitx5/conf"
+FCITX5_XCB_CONF="$FCITX5_CONF_DIR/xcb.conf"
+
+if [[ ! -f $FCITX5_XCB_CONF ]]; then
+  mkdir -p "$FCITX5_CONF_DIR"
+  cp "$OMARCHY_PATH/config/fcitx5/conf/xcb.conf" "$FCITX5_XCB_CONF"
+fi