benchmark: unset python version (#10300)

benchmark/PaddleOCR_DBNet/test_tipc/configs/det_res50_db/train_infer_python.txt

 ===========================train_params===========================
 model_name:det_res50_db
-python:python3.7
+python:python
 gpu_list:0|0,1
 trainer.use_gpu:True|True
 amp:null
@@ -13,29 +13,29 @@ train_infer_img_dir:imgs/paper/db.jpg
 null:null
 ##
 trainer:norm_train
-norm_train:tools/train.py --config_file config/icdar2015_resnet50_FPN_DBhead_polyLR.yaml -o trainer.log_iter=1 trainer.enable_eval=False dataset.train.loader.shuffle=false arch.backbone.pretrained=False 
+norm_train:tools/train.py --config_file config/icdar2015_resnet50_FPN_DBhead_polyLR.yaml -o trainer.log_iter=1 trainer.enable_eval=False dataset.train.loader.shuffle=false arch.backbone.pretrained=False
 quant_export:null
 fpgm_export:null
 distill_train:null
 null:null
 null:null
 ##
-===========================eval_params=========================== 
+===========================eval_params===========================
 eval:null
 null:null
 ##
 ===========================infer_params===========================
 trainer.output_dir:./output/
 trainer.resume_checkpoint:
-norm_export:tools/export_model.py --config_file config/icdar2015_resnet50_FPN_DBhead_polyLR.yaml -o 
-quant_export:null 
+norm_export:tools/export_model.py --config_file config/icdar2015_resnet50_FPN_DBhead_polyLR.yaml -o
+quant_export:null
 fpgm_export:null
 distill_export:null
 export1:null
 export2:null
 ##
 train_model:./inference/det_r50_vd_db_v2.0_train/best_accuracy
-infer_export:tools/export_model.py --config_file config/icdar2015_resnet50_FPN_DBhead_polyLR.yaml -o 
+infer_export:tools/export_model.py --config_file config/icdar2015_resnet50_FPN_DBhead_polyLR.yaml -o
 infer_quant:False
 inference:tools/infer.py
 --use_gpu:True|False
@@ -58,4 +58,4 @@ epoch:2
 --profiler_options:batch_range=[10,20];state=GPU;tracer_option=Default;profile_path=model.profile
 flags:FLAGS_eager_delete_tensor_gb=0.0;FLAGS_fraction_of_gpu_memory_to_use=0.98;FLAGS_conv_workspace_size_limit=4096
 ===========================to_static_train_benchmark_params===========================
-to_static_train:trainer.to_static=true
\ No newline at end of file
+to_static_train:trainer.to_static=true