add cmocka

.github/workflows/build.yml

@@ -15,6 +15,8 @@ jobs:
     - uses: actions/checkout@v3
     - name: download munit
       run: git submodule init && git submodule update
+    - name: install cmocka
+      run: sudo apt install -y libcmocka-dev
     - name: configure
       run: ./configure
     - name: build tests