server: continue to update other slots on embedding concurrent request (#5699)

* server: #5655 - continue to update other slots on embedding concurrent request.

* server: tests: add multi users embeddings as fixed

* server: tests: adding OAI compatible embedding concurrent endpoint

* server: tests: adding OAI compatible embedding with multiple inputs

examples/server/server.cpp

@@ -1836,7 +1836,7 @@ struct llama_server_context
                     send_embedding(slot);
                     slot.release();
                     slot.i_batch = -1;
-                    return true;
+                    continue;
                 }
 
                 completion_token_output result;