fix(boards): Properly note ZMK compat for xiao_rp2040/zmk variant (#3326)

Add missing board Kconfig file for properly noting ZMK board compat and
enabling boot mode retention for the `xiao_rp2040//zmk` board variant.

app/boards/seeed/xiao_rp2040/Kconfig.xiao_rp2040

@@ -0,0 +1,10 @@
+# Copyright (c) 2026 Pete Johanson
+# SPDX-License-Identifier: MIT
+
+config BOARD_XIAO_RP2040
+    select ZMK_BOARD_COMPAT if BOARD_XIAO_RP2040_RP2040_ZMK
+    imply RETAINED_MEM if BOARD_XIAO_RP2040_RP2040_ZMK
+    imply RETENTION if BOARD_XIAO_RP2040_RP2040_ZMK
+    imply RETENTION_BOOT_MODE if BOARD_XIAO_RP2040_RP2040_ZMK
+
+

docs/package-lock.json

@@ -13971,9 +13971,9 @@
       }
     },
     "node_modules/lodash": {
-      "version": "4.18.1",
-      "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.18.1.tgz",
-      "integrity": "sha512-dMInicTPVE8d1e5otfwmmjlxkZoUpiVLwyeTdUsi/Caj/gfzzblBcCE5sRHV/AsjuCmxWrte2TNGSYuCeCq+0Q==",
+      "version": "4.17.23",
+      "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.23.tgz",
+      "integrity": "sha512-LgVTMpQtIopCi79SJeDiP0TfWi5CNEc/L/aRdTh3yIvmZXTnheWpKjSZhnvMl8iXbC1tFg9gdHHDMLoV7CnG+w==",
       "license": "MIT"
     },
     "node_modules/lodash-es": {