add __init__.py

this fixes relative import issues

solana/yellowstone/python/pumpfun/generated/__init__.py

@@ -0,0 +1,11 @@
+import sys
+from pathlib import Path
+
+current_dir = str(Path(__file__).parent)
+if current_dir not in sys.path:
+        sys.path.append(current_dir)
+
+from . import geyser_pb2
+from . import geyser_pb2_grpc
+from . import solana_storage_pb2
+from . import solana_storage_pb2_grpc