Add minimal environment hlrs

environments/hlrs/spack.yaml

@@ -0,0 +1,10 @@
+# This is a Spack Environment file.
+#
+# It describes a set of packages to be installed, along with
+# configuration settings.
+spack:
+  # add package specs to the `specs` list
+  specs: []
+  view: false
+  concretizer:
+    unify: when_possible