test-release.sh: Remove test-suite from LLVM_ENABLE_PROJECTS

[rovka]

Summary

I think this was just being ignored before, but now it crashes because
we're checking if the projects that we're trying to enable are valid.
There is no test-suite project (it's a separate repo with separate
handling), so we should never try to enable it.

[tstellar]

LGTM. Can you cherry-pick this to the release/14.x branch after you commit to main.

llvm/utils/release/test-release.sh

if [ $do_libs = "yes" ]; then
   runtimes="$runtimes libcxx"
   if [ $do_libcxxabi = "yes" ]; then
     runtimes="$runtimes libcxxabi"
   fi
   if [ $do_libunwind = "yes" ]; then
     runtimes="$runtimes libunwind"
   fi
 fi
-case $do_test_suite in
-  yes|export-only)
-    projects="$projects test-suite"
-    ;;
-esac
 if [ $do_openmp = "yes" ]; then
   projects="$projects openmp"
 fi
 if [ $do_lld = "yes" ]; then
   projects="$projects lld"
 fi
 if [ $do_lldb = "yes" ]; then
   projects="$projects lldb"