Start compacting GC after finishing indexing

Author: vinistock

lib/ruby_lsp/server.rb

@@ -876,6 +876,11 @@ def perform_initial_indexing
           send_message(Notification.window_show_error("Error while indexing: #{error.message}"))
         end
 
+        # Indexing produces a high number of short lived object allocations. That might lead to some fragmentation and
+        # an unnecessarily expanded heap. Compacting ensures that the heap is as small as possible and that future
+        # allocations and garbage collections are faster
+        GC.compact
+
         # Always end the progress notification even if indexing failed or else it never goes away and the user has no
         # way of dismissing it
         end_progress("indexing-progress")