[DOCS] More clarity on security model of RPC server (#17382)

This PR updates the python docstrings to include
more clarity on RPC server security model.

python/tvm/rpc/__init__.py

@@ -23,6 +23,11 @@
 
 The test program compiles the program on local server,
 upload and run remote RPC server, get the result back to verify correctness.
+
+TVM RPC server assumes that the user is trusted and needs to be
+used in a trusted network environment and encrypted channels.
+It allows writings of arbitrary files into the server and provide
+full remote code execution capabilities to anyone who can access this API.
 """
 
 from .server import Server

python/tvm/rpc/server.py

@@ -474,6 +474,11 @@ class Server(object):
 
     Note
     ----
+    TVM RPC server assumes that the user is trusted and needs to be
+    used in a trusted network environment and encrypted channels.
+    It allows writings of arbitrary files into the server and provide
+    full remote code execution capabilities to anyone who can access this API.
+
     The RPC server only sees functions in the tvm namespace.
     To bring additional custom functions to the server env, you can use server_init_callback.