create_newcase is copying over more Depends files to the case directory than expected

[worleyph]

In CIME2, the create_newcase script logic was as follows:

 # Copy Depends files if they exist 
 if( -e "$machdir/Depends.$mach.$compiler" ) {
     $sysmod = "cp $machdir/Depends.$mach.$compiler $caseroot/";
     system($sysmod) == 0 or die "ERROR: $sysmod failed: $?\n";
 }else{
 if( -e "$machdir/Depends.$mach" ) {
     $sysmod = "cp $machdir/Depends.$mach $caseroot/";
     system($sysmod) == 0 or die "ERROR: $sysmod failed: $?\n";
 }
 if( -e "$machdir/Depends.$compiler" ) {
     $sysmod = "cp $machdir/Depends.$compiler $caseroot/";
     system($sysmod) == 0 or die "ERROR: $sysmod failed: $?\n";
 }
 }

and either a Depends.$mach.$compiler file was copied into the case directory OR (exclusive)
a Depends.$mach or (inclusive) a Depends.$compiler file was copied.

In CIME5 we are getting both Depends.$mach.$compiler and Depends.$compiler, for example.

This is a change in behavior. If not deliberate, then it is a bug. POCs for systems have been maintaining only Depends.$mach.$compiler to my understanding, at least on Titan.