Remove '%clang' requirement from several ACTS users (#44)

Removed '%clang' requirement from multiple packages in the YAML configuration.

Author: wdconinc

spack-environment/packages.yaml

@@ -18,7 +18,6 @@ packages:
     - any_of: [build_type=Release, '@:']
   acts:
     require:
-    - '%clang'
     - '@39.2.0'
     - cxxstd=20 +dd4hep ~edm4hep +examples +fatras +geant4 +json +onnx +podio +python +svg +tgeo +pr4496 +pr4502 +pr4620
   actsvg:
@@ -125,7 +124,6 @@ packages:
     - '@1.1.14'
   eicrecon:
     require:
-    - '%clang'
     - '@1.30.1' # EICRECON_VERSION
   eigen:
     require:
@@ -229,7 +227,6 @@ packages:
     - -ipo +podio +root +zmq
   juggler:
     require:
-    - '%clang'
     - '@15.0.2' # JUGGLER_VERSION
     - cxxstd=20
   julia: