Re-enable cmake --target cpptest -j 2

Author: rwgk

.github/workflows/upstream.yml

@@ -1,4 +1,3 @@
-
 name: Upstream
 
 on:
@@ -65,8 +64,8 @@ jobs:
     - name: Python tests C++11
       run: cmake --build build11 --target pytest -j 2
 
-    # - name: C++11 tests
-    #   run: cmake --build build11  --target cpptest -j 2
+    - name: C++11 tests
+      run: cmake --build build11  --target cpptest -j 2
 
     - name: Interface test C++11
       run: cmake --build build11 --target test_cmake_build
@@ -86,8 +85,8 @@ jobs:
     - name: Python tests
       run: cmake --build build17 --target pytest
 
-    # - name: C++ tests
-    #   run: cmake --build build17 --target cpptest
+    - name: C++ tests
+      run: cmake --build build17 --target cpptest
 
     # Third build - C++17 mode with unstable ABI
     - name: Configure (unstable ABI)