upgraded tensorflow (#120)

Author: ChaoPang

pyproject.toml

@@ -46,9 +46,9 @@ dependencies = [
     "PyYAML==6.0.1",
     "scikit-learn==1.4.0",
     "scipy==1.12.0",
-    "tensorflow==2.15.0",
-    "tensorflow-metal==1.1.0; sys_platform == 'darwin'", # macOS only
-    "tensorflow-datasets==4.5.2",
+    "tensorflow>=2.15.0",
+    "tensorflow-metal>=1.1.0; sys_platform == 'darwin'", # macOS only
+    "tensorflow-datasets>=4.5.2",
     "tqdm>=4.66.1",
     "torch==2.4.0",
     "tokenizers>=0.19.0",