Fix the code hang while caching nodes if search is run with a single thread (#590)

* Fixing other places with the single search thread hang issue

* Fixing other places with the single search thread hang issue

* Adding overwrite option to delete old versions

* Add a run id to files to avoid naming conflicts

---------

Co-authored-by: Gopal Srinivasa <gopalsr@microsoft.com>

.github/workflows/build-python-pdoc.yml

@@ -47,7 +47,8 @@ jobs:
         with:
           name: dependencies
           path: |
-            dependencies_documentation.txt
+            ${{ github.run_id }}-dependencies_documentation.txt
+            overwrite: true
       - name: Archive documentation artifacts
         uses: actions/upload-artifact@v4
         with:

src/pq_flash_index.cpp

@@ -365,11 +365,6 @@ void PQFlashIndex<T, LabelT>::cache_bfs_levels(uint64_t num_nodes_to_cache, std:
     }
     diskann::cout << "Caching " << num_nodes_to_cache << "..." << std::endl;
 
-    // borrow thread data
-    ScratchStoreManager<SSDThreadData<T>> manager(this->_thread_data);
-    auto this_thread_data = manager.scratch_space();
-    IOContext &ctx = this_thread_data->ctx;
-
     std::unique_ptr<tsl::robin_set<uint32_t>> cur_level, prev_level;
     cur_level = std::make_unique<tsl::robin_set<uint32_t>>();
     prev_level = std::make_unique<tsl::robin_set<uint32_t>>();