fix: add acts-dd4hep again, required for older geometry

spack.yaml

@@ -2,6 +2,7 @@ spack:
   specs:
     - acts@21.1.0 +dd4hep +identification +json +tgeo +examples +fatras +geant4 +python
     - actsvg@0.4.26 +examples
+    - acts-dd4hep@1.0.1
     - afterburner@0.1.2 +root +zlib
     - cairo@1.16.0 +fc+ft+X+pdf+gobject
     - clhep@2.4.6.0 cxxstd=17