Revert "Disable NVIDIA_TF32_OVERRIDE by default for better precision." (PaddlePaddle#75907)

* Revert "Disable CUBLAS TF32 for default for better precision. (PaddlePaddle#75476)"

This reverts commit fcf3c3f.

* Update __init__.py

test=document_fix

Author: A-nnonymous

python/paddle/base/__init__.py

@@ -164,9 +164,6 @@ def __bootstrap__():
 
     os.environ['OMP_NUM_THREADS'] = str(num_threads)
 
-    if os.getenv('NVIDIA_TF32_OVERRIDE', None) is None:
-        os.environ['NVIDIA_TF32_OVERRIDE'] = '0'
-
     if os.getenv('MKL_NUM_THREADS', None) is None:
         os.environ['MKL_NUM_THREADS'] = str(int(0.8 * os.cpu_count()))