Fix workflow and submodule configuration

Update mocks submodule to use the upstream iv-org repository
(https://github.com/iv-org/mocks) instead of the inaccessible
NeskireDK fork path.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.github/workflows/build-arik-container.yml

@@ -11,6 +11,8 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v6
+        with:
+          submodules: true
 
       - name: Install required APT packages
         run: sudo apt install -y libsqlite3-dev

.gitmodules

@@ -1,3 +1,3 @@
 [submodule "mocks"]
 	path = mocks
-	url = ../mocks
+	url = https://github.com/iv-org/mocks