gradient accumulation tests, embeddings w pad_token fix, smaller models (#2059)

* add more test cases for gradient accumulation and fix zero3

* swap out for smaller model

* fix missing return

* fix missing pad_token in config

* support concurrency for multigpu testing

* cast empty deepspeed to empty string for zero3 check

* fix temp_dir as fixture so parametrize works properly

* fix test file for multigpu evals

* don't use default

* don't use default for fsdp_state_dict_type

* don't use llama tokenizer w smollm

* also automatically cancel multigpu for concurrency

src/axolotl/utils/models.py

@@ -238,6 +238,7 @@ def load_tokenizer(cfg):
                         x in cfg.lora_modules_to_save for x in lora_modules_to_save
                     )
                 )
+                and k != "pad_token"
             ):
                 lora_modules_to_save = ", ".join(
                     [f"`{x}`" for x in lora_modules_to_save]