Merge branch 'ndk/machinefiles/perlmutter-revert-gnu-compiler-version' into next (PR #7872)

Undo a change in #7740, by changing only the GNU compiler version (from 13.2 to 12.3) for pm-cpu/pm-gpu.
Fixes #7871
Fixes #7843
Fixes #7842

Should be BFB for vanilla E3SM cases, but not for eamxx cases.

Author: ndkeen

cime_config/machines/config_machines.xml

@@ -219,7 +219,7 @@
 
       <modules compiler="gnu">
         <command name="load">PrgEnv-gnu/8.5.0</command>
-        <command name="load">gcc-native/13.2</command>
+        <command name="load">gcc-native/12.3</command>
         <command name="load">cray-libsci/24.07.0</command>
       </modules>
 
@@ -409,7 +409,7 @@
 
       <modules compiler="gnu.*">
         <command name="load">PrgEnv-gnu/8.5.0</command>
-        <command name="load">gcc-native/13.2</command>
+        <command name="load">gcc-native/12.3</command>
       </modules>
 
       <modules compiler="nvidia.*">
@@ -425,7 +425,7 @@
       <modules compiler="nvidiagpu">
         <command name="load">cudatoolkit/12.9</command>
         <command name="load">craype-accel-nvidia80</command>
-        <command name="load">gcc-native-mixed/13.2</command>
+        <command name="load">gcc-native-mixed/12.3</command>
       </modules>
 
       <modules compiler="gnu">