ci: enable test runs on CI

Author: satya-das

.github/workflows/cmake-multi-platform.yml

@@ -65,6 +65,7 @@ jobs:
         -DCMAKE_CXX_COMPILER=${{ matrix.cpp_compiler }}
         -DCMAKE_C_COMPILER=${{ matrix.c_compiler }}
         -DCMAKE_BUILD_TYPE=${{ matrix.build_type }}
+        -DCPPPARSER_BUILD_TESTS=ON
         -S ${{ github.workspace }}
 
     - name: Build