common: add `LLAMA_ARG_OVERRIDE_TENSOR` env var for `-ot` arg (#18267)

common/arg.cpp

@@ -2087,7 +2087,7 @@ common_params_context common_params_parser_init(common_params & params, llama_ex
         "override tensor buffer type", [](common_params & params, const std::string & value) {
             parse_tensor_buffer_overrides(value, params.tensor_buft_overrides);
         }
-    ));
+    ).set_env("LLAMA_ARG_OVERRIDE_TENSOR"));
     add_opt(common_arg(
         {"-otd", "--override-tensor-draft"}, "<tensor name pattern>=<buffer type>,...",
         "override tensor buffer type for draft model", [](common_params & params, const std::string & value) {