Require accelerate>=0.20.3 as transformers do (#383)

setup.cfg

@@ -33,7 +33,7 @@ python_requires = >=3.8,<3.11
 install_requires =
     torch>=1.12
     bitsandbytes==0.40.1.post1
-    accelerate>=0.16.0,<0.21.0
+    accelerate>=0.20.3,<0.21.0
     huggingface-hub>=0.11.1,<1.0.0
     tokenizers>=0.13.3
     transformers>=4.31.0,<5.0.0