ci: Fix RIOT port build

RIOT reordered examples fodler structure.

Author: sjanc

.github/workflows/build_ports.yml

@@ -51,7 +51,7 @@ jobs:
              rm RIOT/pkg/nimble/patches/ -rf
              sed -i 's|PKG_URL.*|PKG_URL = '$(pwd)'|' RIOT/pkg/nimble/Makefile
              sed -i 's|PKG_VERSION.*|PKG_VERSION = '${{ github.sha }}'|' RIOT/pkg/nimble/Makefile
-             make -C RIOT/examples/nimble_gatt
+             make -C RIOT/examples/networking/ble/nimble/nimble_gatt
       - name: Build Nuttx port
         shell: bash
         if: success() || failure()