fix ci; specify flash-attn version

Author: YeAnbang

.github/workflows/run_chatgpt_examples.yml

@@ -47,6 +47,7 @@ jobs:
       - name: Install Transformers
         run: |
           pip install --no-cache-dir transformers==4.36.2
+          pip install flash-attn==2.7.4.post1 --no-build-isolation
 
       - name: Execute Examples
         run: |