Remove a common redundant prefix

The model oftens starts its responses by 'This pull request' which
is redundant. Let's remove it if that's the case.

I tried to make it respond without it but it was affecting the rest of the results
so I guess this is the 'cheapest' way to remove that prefix.

autofill_description.py

@@ -192,6 +192,12 @@ def main():
     )
 
     generated_pr_description = openai_response.choices[0].message.content
+    redundant_prefix = "This pull request "
+    if generated_pr_description.startswith(redundant_prefix):
+        generated_pr_description = generated_pr_description[len(redundant_prefix) :]
+        generated_pr_description = (
+            generated_pr_description[0].upper() + generated_pr_description[1:]
+        )
     print(f"Generated pull request description: '{generated_pr_description}'")
     issues_url = "%s/repos/%s/issues/%s" % (
         github_api_url,