update requirements.txt and README to include RAdamScheduleFree optimizer support

Author: kohya-ss

README.md

@@ -14,6 +14,12 @@ The command to install PyTorch is as follows:
 
 ### Recent Updates
 
+Dec 15, 2024:
+
+- RAdamScheduleFree optimizer is supported. PR [#1830](https://github.com/kohya-ss/sd-scripts/pull/1830) Thanks to nhamanasu!
+  - Update to `schedulefree==1.4` is required. Please update individually or with `pip install --use-pep517 --upgrade -r requirements.txt`.
+  - Available with `--optimizer_type=RAdamScheduleFree`. No need to specify warm up steps as well as learning rate scheduler.
+
 Dec 7, 2024:
 
 - The option to specify the model name during ControlNet training was different in each script. It has been unified. Please specify `--controlnet_model_name_or_path`. PR [#1821](https://github.com/kohya-ss/sd-scripts/pull/1821) Thanks to sdbds!

requirements.txt

@@ -9,7 +9,7 @@ pytorch-lightning==1.9.0
 bitsandbytes==0.44.0
 prodigyopt==1.0
 lion-pytorch==0.0.6
-schedulefree==1.2.7
+schedulefree==1.4
 tensorboard
 safetensors==0.4.4
 # gradio==3.16.2