Compile ACTS with GEANT4 flags=ON (#5048)

* Compile with GEANT4 flags=ON
* Add ninja flag
* GEANT4 is also run-time requirement - not only build requirement
* specify explicitly where to search for Geant4

---------

Co-authored-by: Sandro Wenzel <[email protected]>

Author: altsybee

acts.sh

@@ -3,12 +3,14 @@ version: "v23.5.0-alice"
 requires:
   - ROOT
   - pythia
+  - GEANT4
 build_requires:
   - "GCC-Toolchain:(?!osx)"
   - CMake
   - boost
   - Eigen3
   - alibuild-recipe-tools
+  - ninja
 source: https://github.com/AliceO2Group/acts.git
 ---
 #!/bin/bash -ex
@@ -20,8 +22,12 @@ cmake $SOURCEDIR -DCMAKE_INSTALL_PREFIX=$INSTALLROOT       \
                  -DACTS_BUILD_EXAMPLES_PYTHON_BINDINGS=ON  \
 		 -DACTS_BUILD_ANALYSIS_APPS=ON             \
                  -DACTS_BUILD_EXAMPLES_PYTHIA8=ON          \
-                 -DCMAKE_PREFIX_PATH=${PYTHIA_ROOT}        
-
+                 -DCMAKE_PREFIX_PATH=${PYTHIA_ROOT}  	   \
+                 -DACTS_BUILD_PLUGIN_GEANT4=ON		   \
+                 -DACTS_BUILD_FATRAS_GEANT4=ON		   \
+                 -DACTS_BUILD_EXAMPLES_GEANT4=ON           \
+		 -DGeant4_DIR=${GEANT4_ROOT}/lib           \
+                 -G Ninja 
 
 cmake --build . -- ${JOBS:+-j$JOBS} install