See if using only one thread to build prevents running out of ram on github...

See if using only one thread to build prevents running out of ram on github actions when building windows examples

.github/workflows/build_cpp.yml

@@ -112,7 +112,7 @@ jobs:
     - name: Test
       run: ${{ env.build_dir }}/${{ env.config }}/dtest.exe --runall -q
     - name: Build examples, etc
-      run: cmake --build ${{ env.build_dir }} --config ${{ env.config }} --parallel 2
+      run: cmake --build ${{ env.build_dir }} --config ${{ env.config }} --parallel 1
 
   macos-latest:
     runs-on: 'macos-latest'