fix: Ignore python.packages when requirements_txt is provided (#5421)

issue 5380 fix

Author: qimcis

src/_bentoml_sdk/images.py

@@ -397,7 +397,7 @@ def populate_image_from_build_config(
         image.requirements_file(
             resolve_user_filepath(python_options.requirements_txt, build_ctx)
         )
-    if python_options.packages:
+    elif python_options.packages:
         image.python_packages(*python_options.packages)
     if docker_options.setup_script:
         image.run_script(docker_options.setup_script)

src/bentoml/_internal/cloud/deployment.py

@@ -1570,8 +1570,9 @@ def _build_requirements_txt(bento_dir: str, image: Image | None) -> bytes:
     if filename and os.path.exists(fullpath := os.path.join(bento_dir, filename)):
         with open(fullpath, "rb") as f:
             content = f.read().rstrip(b"\n") + b"\n"
-    for package in config.python.packages or []:
-        content += f"{package}\n".encode()
+    elif config.python.packages:
+        for package in config.python.packages:
+            content += f"{package}\n".encode()
     if image and image.python_requirements:
         content += image.python_requirements.encode()
     bentoml_requirement = get_bentoml_requirement()