Fix nightly build

Signed-off-by: Pol Henarejos <pol.henarejos@cttc.es>

.github/workflows/nightly.yml

@@ -1,11 +1,6 @@
 name: "Nightly deploy"
 
 on:
-  push:
-    branches: [ "main", "development" ]
-  pull_request:
-    # The branches below must be a subset of the branches above
-    branches: [ "main", "development" ]
   schedule:
     - cron: '0 2 * * *'
   workflow_dispatch:
@@ -25,6 +20,8 @@ jobs:
           ref: ${{ matrix.refs }}
           submodules: 'recursive'
       - name : Build
+        env:
+          PICO_SDK_PATH: ../pico-sdk
         run: |
            ./workflows/autobuild.sh
            ./build_pico_fido.sh