sysconfig: Add get_default_scheme and get_preferred_scheme (#8265)

Author: q0w

stdlib/sysconfig.pyi

@@ -1,4 +1,6 @@
+import sys
 from typing import IO, Any, overload
+from typing_extensions import Literal
 
 __all__ = [
     "get_config_h_filename",
@@ -20,6 +22,11 @@ def get_config_vars() -> dict[str, Any]: ...
 @overload
 def get_config_vars(arg: str, *args: str) -> list[Any]: ...
 def get_scheme_names() -> tuple[str, ...]: ...
+
+if sys.version_info >= (3, 10):
+    def get_default_scheme() -> str: ...
+    def get_preferred_scheme(key: Literal["prefix", "home", "user"]) -> str: ...
+
 def get_path_names() -> tuple[str, ...]: ...
 def get_path(name: str, scheme: str = ..., vars: dict[str, Any] | None = ..., expand: bool = ...) -> str: ...
 def get_paths(scheme: str = ..., vars: dict[str, Any] | None = ..., expand: bool = ...) -> dict[str, str]: ...