Fix type not subscriptable for versions below 3.10

Author: ItsDrike

mcproto/packets/map.py

@@ -12,7 +12,7 @@
 __all__ = ["PacketMap"]
 
 
-class PacketMap(VersionMap[tuple[PacketDirection, GameState, int], type[Packet]]):
+class PacketMap(VersionMap["tuple[PacketDirection, GameState, int]", "type[Packet]"]):
     SUPPORTED_VERSIONS: ClassVar[set[int]] = {757}
     COMPATIBLE_FALLBACK_VERSIONS: ClassVar[set[int]] = set()
     _SEARCH_DIR_QUALNAME: ClassVar[str] = "mcproto.packets"