Fix snap damage "self" conflicting w python keyword

scripts/generate_messages.py

@@ -209,8 +209,8 @@ f"""
 
 def fix_name_conflict(name: str) -> str:
     # https://peps.python.org/pep-0008/#descriptive-naming-styles
-    if name == 'pass':
-        return 'pass_'
+    if name in ('pass', 'self'):
+        return f'{name}_'
     return name
 
 def name_to_camel(name_list: list[str]) -> str: