.github: remove redundant make invocation

.github/workflows/c-cpp.yml

@@ -4,15 +4,10 @@ on: [push, pull_request]
 
 jobs:
   build:
-
     runs-on: ubuntu-latest
-
     steps:
     - uses: actions/checkout@v3
     - name: Install dependencies
       run: sudo apt-get install -y clang-tools check
     - name: make
       run: make
-    - name: make test
-      run: make test
-