Revert "Separable module configurations (#22588)" (#23674)

This reverts commit cefbe48c89.

etc/spack/defaults/config.yaml

@@ -33,6 +33,13 @@ config:
   template_dirs:
     - $spack/share/spack/templates
 
+
+  # Locations where different types of modules should be installed.
+  module_roots:
+    tcl:    $spack/share/spack/modules
+    lmod:   $spack/share/spack/lmod
+
+
   # Temporary locations Spack can try to use for builds.
   #
   # Recommended options are given below.

etc/spack/defaults/darwin/modules.yaml

@@ -14,9 +14,8 @@
 #   ~/.spack/modules.yaml
 # -------------------------------------------------------------------------
 modules:
-  default:
-    prefix_inspections:
-      lib:
-        - DYLD_FALLBACK_LIBRARY_PATH
-      lib64:
-        - DYLD_FALLBACK_LIBRARY_PATH
+  prefix_inspections:
+    lib:
+      - DYLD_FALLBACK_LIBRARY_PATH
+    lib64:
+      - DYLD_FALLBACK_LIBRARY_PATH

etc/spack/defaults/linux/modules.yaml

@@ -14,9 +14,8 @@
 #   ~/.spack/modules.yaml
 # -------------------------------------------------------------------------
 modules:
-  default:
-    prefix_inspections:
-      lib:
-        - LD_LIBRARY_PATH
-      lib64:
-        - LD_LIBRARY_PATH
+  prefix_inspections:
+    lib:
+      - LD_LIBRARY_PATH
+    lib64:
+      - LD_LIBRARY_PATH

etc/spack/defaults/modules.yaml

@@ -14,7 +14,8 @@
 #   ~/.spack/modules.yaml
 # -------------------------------------------------------------------------
 modules:
-  # Paths to check when creating modules for all module sets
+  enable:
+    - tcl
   prefix_inspections:
     bin:
       - PATH
@@ -33,17 +34,6 @@ modules:
     '':
       - CMAKE_PREFIX_PATH
 
-  # These are configurations for the module set named "default"
-  default:
-    # Where to install modules
-    roots:
-      tcl:    $spack/share/spack/modules
-      lmod:   $spack/share/spack/lmod
-    # What type of modules to use
-    enable:
-      - tcl
-
-    # Default configurations if lmod is enabled
-    lmod:
-      hierarchy:
-        - mpi
+  lmod:
+    hierarchy:
+      - mpi