[Bug Fix] new sample STFPM to validate fix_hash (#273)

* Use astor instead of ast to unparse source code of paddle model, to avoid unstable result between different python versions.

* fix hash bug cased by python-version 3.10/3.12

Author: HeyDavid633

paddle_samples/PaddleX/STFPM/graph_hash.txt

@@ -0,0 +1 @@
+32db5c97231520cb0081bc48365b4cb65eeda8c2a860564cbce9488f14392121

paddle_samples/PaddleX/STFPM/graph_net.json

@@ -0,0 +1,6 @@
+{
+    "framework": "paddle",
+    "model_name": "STFPM",
+    "num_devices_required": 1,
+    "num_nodes_required": 1
+}

paddle_samples/PaddleX/STFPM/input_meta.py

@@ -0,0 +1,9 @@
+class Program_weight_tensor_data_0:
+    name = "data_0"
+    shape = [1, 3, 256, 256]
+    dtype = "float32"
+    min_val = float("-1.54422")
+    max_val = float("1.21516")
+    mean = float("-0.201062")
+    std = float("0.553945")
+    data = None