Ensures that apfelxx-config is found

Author: Radonirinaunimi

.github/workflows/ci-test.yml

@@ -33,7 +33,7 @@ jobs:
           cmake .. -DCMAKE_INSTALL_PREFIX=$HOME/.local
           make -j$(nproc)
           make install
-          echo "PATH=$HOME/.local/bin:$PATH" >> $GITHUB_ENV
+          echo "$HOME/.local/bin" >> $GITHUB_PATH
           echo "LD_LIBRARY_PATH=$HOME/.local/lib:$LD_LIBRARY_PATH" >> $GITHUB_ENV
 
       # ---- Build pineapfel ----