Revert "Restore CUDA-based unit tests (#6518)"

This reverts commit dc52b17c4d.

ci/test-stable.sh

@@ -80,7 +80,7 @@ test-stable-perf)
   fi
 
   _ cargo +"$rust_stable" build --bins ${V:+--verbose}
-  _ cargo +"$rust_stable" test --package solana-ledger --package solana-core --lib ${V:+--verbose} -- --nocapture
+  _ cargo +"$rust_stable" test --package solana-core --lib ${V:+--verbose} -- --nocapture
   ;;
 test-local-cluster)
   echo "Executing $testName"

ledger/src/perf_libs.rs

@@ -159,6 +159,7 @@ pub fn init_cuda() {
 }
 
 pub fn api() -> Option<&'static Container<Api<'static>>> {
+    #[cfg(test)]
     {
         static INIT_HOOK: Once = Once::new();
         INIT_HOOK.call_once(|| {