perf: clear residuals after computing direction (#15)

Co-authored-by: mad-cat-lon <113548315+mad-cat-lon@users.noreply.github.com>

src/heretic/main.py

@@ -39,6 +39,7 @@ from .utils import (
     get_trial_parameters,
     load_prompts,
     print,
+    empty_cache,
 )
 
 
@@ -195,6 +196,9 @@ def run():
         p=2,
         dim=1,
     )
+    # we don't need the residuals after computing refusal directions
+    del good_residuals, bad_residuals
+    empty_cache()
 
     trial_index = 0
     start_time = time.perf_counter()