refactor: modernize Union type syntax to use < /dev/null | operator

Replace `Union[X, Y]` with `X | Y` syntax for cleaner type annotations.
Applied to type aliases, function signatures, and complex type definitions
for improved readability and reduced import dependencies.

Python 3.10+ feature - more concise and intuitive union syntax.

Author: danceratopz

src/cli/order_fixtures.py

@@ -17,12 +17,12 @@
 
 import json
 from pathlib import Path
-from typing import Any, Dict, List, Union, cast
+from typing import Any, Dict, List, cast
 
 import click
 
 
-def recursive_sort(item: Union[Dict[str, Any], List[Any]]) -> Union[Dict[str, Any], List[Any]]:
+def recursive_sort(item: Dict[str, Any] | List[Any]) -> Dict[str, Any] | List[Any]:
     """
     Recursively sorts an item.
 

src/ethereum_test_rpc/rpc.py

@@ -3,7 +3,7 @@
 import time
 from itertools import count
 from pprint import pprint
-from typing import Any, ClassVar, Dict, List, Literal, Union
+from typing import Any, ClassVar, Dict, List, Literal
 
 import requests
 from jwt import encode
@@ -23,7 +23,7 @@
     TransactionByHashResponse,
 )
 
-BlockNumberType = Union[int, Literal["latest", "earliest", "pending"]]
+BlockNumberType = int | Literal["latest", "earliest", "pending"]
 
 
 class SendTransactionExceptionError(Exception):
@@ -111,7 +111,7 @@ class EthRPC(BaseRPC):
 
     transaction_wait_timeout: int = 60
 
-    BlockNumberType = Union[int, Literal["latest", "earliest", "pending"]]
+    BlockNumberType = int | Literal["latest", "earliest", "pending"]
 
     def __init__(
         self,

src/ethereum_test_rpc/types.py

@@ -2,7 +2,7 @@
 
 from enum import Enum
 from hashlib import sha256
-from typing import Annotated, Any, List, Union
+from typing import Annotated, Any, List
 
 from pydantic import AliasChoices, Field, model_validator
 
@@ -97,7 +97,7 @@ class PayloadStatusEnum(str, Enum):
 
 
 class BlockTransactionExceptionWithMessage(
-    ExceptionWithMessage[Union[BlockException, TransactionException]]  # type: ignore
+    ExceptionWithMessage[BlockException | TransactionException]  # type: ignore
 ):
     """Exception returned from the execution client with a message."""
 

src/ethereum_test_types/trie.py

@@ -13,7 +13,6 @@
     Sequence,
     Tuple,
     TypeVar,
-    Union,
     cast,
 )
 
@@ -75,7 +74,7 @@ def encode_account(raw_account_data: FrontierAccount, storage_root: Bytes) -> By
     bytes.fromhex("56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421")
 )
 
-Node = Union[FrontierAccount, Bytes, Uint, U256, None]
+Node = FrontierAccount | Bytes | Uint | U256 | None
 K = TypeVar("K", bound=Bytes)
 V = TypeVar(
     "V",
@@ -133,7 +132,7 @@ class BranchNode:
     value: Extended
 
 
-InternalNode = Union[LeafNode, ExtensionNode, BranchNode]
+InternalNode = LeafNode | ExtensionNode | BranchNode
 
 
 def encode_internal_node(node: Optional[InternalNode]) -> Extended: