generate.py: run ruff format on generated files

Running generate.py standalone previously rewrote _ciphers.py with
formatting that differed from the committed (ruff-formatted) style,
creating spurious diffs. release.py already ran ruff after generation;
now generate.py does too, so both entry points leave the tree in the
same state.

src/aeg/raf.py

@@ -54,6 +54,7 @@ _FLAG_TRUNCATE = 0x02
 _MERKLE_HASH_MIN = 8
 _MERKLE_HASH_MAX = 64
 
+
 @runtime_checkable
 class Storage(Protocol):
     """Backing storage for RAF files. Operations must complete fully or raise OSError."""