fix: python 3.9 support, drop python 3.8 support

had to drop python 3.8 because of pyyaml/cython build issue. pyyaml doesn't release a wheel for 3.8.

brownie_safe.py

@@ -2,6 +2,7 @@
 import warnings
 from copy import copy
 from typing import Dict, List, Optional, Union
+from enum import Enum
 
 import click
 from gnosis.eth import EthereumClient, EthereumNetwork
@@ -17,13 +18,12 @@
 from gnosis.safe.safe_tx import SafeTx
 from gnosis.safe.signatures import signature_split, signature_to_bytes
 from gnosis.safe.api import TransactionServiceApi
+from gnosis.eth.ethereum_client import EthereumNetworkNotSupported
 from hexbytes import HexBytes
 from trezorlib import ethereum, tools, ui
 from trezorlib.client import TrezorClient
 from trezorlib.messages import EthereumSignMessage
 from trezorlib.transport import get_transport
-from enum import Enum
-from gnosis.eth.ethereum_client import EthereumNetworkNotSupported
 
 MULTISEND_CALL_ONLY = '0x40A2aCCbd92BCA938b02010E17A5b8929b49130D'
 multisends = {
@@ -67,7 +67,7 @@ class TransactionServiceBackport(TransactionServiceApi):
         EthereumNetworkBackport.BOBA_NETWORK: "https://safe-transaction.mainnet.boba.network",
     }
 
-    def __init__(self, network: EthereumNetwork, ethereum_client: EthereumClient | None = None, base_url: str | None = None):
+    def __init__(self, network: EthereumNetwork, ethereum_client: Optional[EthereumClient] = None, base_url: Optional[str] = None):
         self.network = network
         self.ethereum_client = ethereum_client
         self.base_url = base_url or self.URL_BY_NETWORK.get(EthereumNetworkBackport(network.value))

pyproject.toml

@@ -1,14 +1,14 @@
 [tool.poetry]
 name = "brownie-safe"
-version = "0.8.0"
+version = "0.8.1"
 description = "Build complex Gnosis Safe transactions and safely preview them in a forked environment."
 authors = ["banteg"]
 license = "MIT"
 repository = "https://github.com/banteg/brownie-safe"
 readme = "readme.md"
 
 [tool.poetry.dependencies]
-python = ">=3.8,<3.11"
+python = ">=3.9,<3.11"
 eth-brownie = "1.19.2"
 safe-eth-py = "4.3.2"
 trezor = "0.13.7"