test: use built-in collection types for type hints (Python 3.9 / PEP 585)

Since Python 3.9, type hinting has become a little less awkward, as for
collection types one doesn't need to import the corresponding
capitalized types (`Dict`, `List`, `Set`, `Tuple`, ...) anymore, but can
use the built-in types directly. [1] [2]
This commit applies the replacement for all Python scripts (i.e. in the
contrib and test folders) for the basic types:
    - typing.Dict  -> dict
    - typing.List  -> list
    - typing.Set   -> set
    - typing.Tuple -> tuple

[1] https://docs.python.org/3.9/whatsnew/3.9.html#type-hinting-generics-in-standard-collections
[2] https://peps.python.org/pep-0585/#implementation for a list of type

test/functional/test_framework/util.py

@@ -20,7 +20,7 @@ import time
 
 from . import coverage
 from .authproxy import AuthServiceProxy, JSONRPCException
-from typing import Callable, Optional, Tuple
+from typing import Callable, Optional
 
 logger = logging.getLogger("TestFramework.utils")
 
@@ -416,7 +416,7 @@ def get_datadir_path(dirname, n):
     return pathlib.Path(dirname) / f"node{n}"
 
 
-def get_temp_default_datadir(temp_dir: pathlib.Path) -> Tuple[dict, pathlib.Path]:
+def get_temp_default_datadir(temp_dir: pathlib.Path) -> tuple[dict, pathlib.Path]:
     """Return os-specific environment variables that can be set to make the
     GetDefaultDataDir() function return a datadir path under the provided
     temp_dir, as well as the complete path it would return."""