Fix typing: Missing return types on methods

src/aleph/vm/hypervisors/firecracker/microvm.py

@@ -104,18 +104,18 @@ def namespace_path(self) -> str:
  return str(self.jailer_base_directory / firecracker_bin_name / str(self.vm_id))
 
  @property
- def jailer_path(self):
+ def jailer_path(self) -> str:
  return os.path.join(self.namespace_path, "root")
 
  @property
- def socket_path(self):
+ def socket_path(self) -> str:
  if self.use_jailer:
  return f"{self.jailer_path}/run/firecracker.socket"
  else:
  return f"/tmp/firecracker-{self.vm_id}.socket"
 
  @property
- def vsock_path(self):
+ def vsock_path(self) -> str:
  if self.use_jailer:
  return f"{self.jailer_path}{VSOCK_PATH}"
  else:
@@ -140,17 +140,17 @@ def __init__(
  self.runtime_config = None
  self.log_queues: list[asyncio.Queue] = []
 
- def to_dict(self):
+ def to_dict(self) -> dict:
  return {
  "jailer_path": self.jailer_path,
  "socket_path": self.socket_path,
  "vsock_path": self.vsock_path,
  **self.__dict__,
  }
 
- def prepare_jailer(self):
+ def prepare_jailer(self) -> None:
  if not self.use_jailer:
- return False
+ return
  system(f"rm -fr {self.jailer_path}")
 
  # system(f"rm -fr {self.jailer_path}/run/")