hints/darwin.sh: drop $prodvers

Unless MACOSX_DEPLOYMENT_TARGET is passed into the build, just ride
the defaults of the OS' toolchain.
This code assumes OS X versioning (10.15.x ) and tries to drop the patch version
from the product version so that you're targetting macOS 10.15, rather
than 10.15.1. Unfortunately with macOS 11 and up, it ends up targetting
the patch version and since we're no longer appending $ld to $lddlflags
we end up with the core targetting the major version and the modules
targetting the patch version. Resulting in warnings
ld: warning: object file (/Users/runner/work/perl5/perl5/cpan/Compress-Raw-Bzip2/Bzip2.o) was built for newer 'macOS' version (14.7) than being linked (14.0)

Author: sevan

hints/darwin.sh

@@ -322,28 +322,6 @@ EOM
       ;;
     esac
 
-    # Keep the prodvers leading whitespace (Configure magic).
-    # Cannot use $osvers here since that is the kernel version.
-    # sw_vers output                 what we want
-    # "ProductVersion:    10.10.5"   "10.10"
-    # "ProductVersion:    10.11"     "10.11"
-        prodvers=`sw_vers|awk '/^ProductVersion:/{print $2}'|awk -F. '{print $1"."$2}'`
-    case "$prodvers" in
-    [1-9][0-9].*)
-      add_macosx_version_min ccflags $prodvers
-      add_macosx_version_min ldflags $prodvers
-      ;;
-    *)
-      cat <<EOM >&4
-
-*** Unexpected product version $prodvers.
-***
-*** Try running sw_vers and see what its ProductVersion says.
-
-EOM
-      exit 1
-    esac
-
     darwin_major=$(echo $osvers|awk -F. '{print $1}')
 
     # macOS 10.12 (darwin 16.0.0) deprecated syscall().