add peft as an additional dependency for gguf

Author: sayakpaul

.github/workflows/nightly_tests.yml

@@ -417,7 +417,7 @@ jobs:
             additional_deps: ["peft"]
           - backend: "gguf"
             test_location: "gguf"
-            additional_deps: []
+            additional_deps: ["peft"]
           - backend: "torchao"
             test_location: "torchao"
             additional_deps: []