[GHA] FIX [appveyor skip]

Author: KrisThielemans

.github/workflows/build-test.yml

@@ -304,17 +304,18 @@ jobs:
 
           if test "${{matrix.parallelproj}}XX" == "ONXX"; then
              git clone --depth 20 https://github.com/KUL-recon-lab/libparallelproj/
+             cd libparallelproj
              git checkout v2.0.3
-             mkdir parallelproj/build
-             cd parallelproj/build
+             mkdir build
+             cd build
              if test "${{matrix.cuda_version}}" == "0"; then
                  cmake --preset default
                  # extra_args="-DSKIP_CUDA_LIB:BOOL=ON"
              fi
              cmake .. -DCMAKE_INSTALL_PREFIX=${CMAKE_INSTALL_PREFIX} ${extra_args}
              cmake --build . --target install --config Release
              cd ../..
-             rm -rf parallelproj
+             rm -rf libparallelproj
           fi
 
           # Install ROOT (warning: brittle due to OS versions etc)