[misc] fix collect env (#8894)

Author: youkaichao

collect_env.py

@@ -267,13 +267,23 @@ def get_neuron_sdk_version(run_lambda):
 
 
 def get_vllm_version():
+    version = ""
     try:
         import vllm
-        return vllm.__version__ + "@" + vllm.__commit__
+        version = vllm.__version__
     except Exception:
-        # old version of vllm does not have __commit__
-        return 'N/A'
-
+        pass
+    commit = ""
+    try:
+        import vllm
+        commit = vllm.__commit__
+    except Exception:
+        pass
+    if version != "" and commit != "":
+        return f"{version}@{commit}"
+    if version == "" and commit == "":
+        return "N/A"
+    return version or commit
 
 def summarize_vllm_build_flags():
     # This could be a static method if the flags are constant, or dynamic if you need to check environment variables, etc.