Update cmake.yml

Adding submodules to the checkout for json library used in one of the submprojects.

Author: sdavtaker

.github/workflows/cmake.yml

@@ -19,6 +19,8 @@ jobs:
 
     steps:
     - uses: actions/checkout@v3
+      with:
+        submodules: true
 
     # Install dependencies
     - name: boost