add llama-completion to completion-bash executables (#17976)

common/arg.cpp

@@ -639,6 +639,7 @@ static void common_params_print_completion(common_params_context & ctx_arg) {
         "llama-batched-bench",
         "llama-bench",
         "llama-cli",
+        "llama-completion",
         "llama-convert-llama2c-to-ggml",
         "llama-cvector-generator",
         "llama-embedding",