Use Python 3.10 sysconfig.get_preferred_scheme()

This function is introduced to 3.10 to do precisely what we want, so
let's use it if possible.

Author: uranusjr

src/pip/_internal/locations/_sysconfig.py

@@ -24,6 +24,8 @@
 
 _AVAILABLE_SCHEMES = set(sysconfig.get_scheme_names())
 
+_HAS_PREFERRED_SCHEME_API = sys.version_info >= (3, 10)
+
 
 def _infer_prefix() -> str:
     """Try to find a prefix scheme for the current platform.
@@ -39,6 +41,8 @@ def _infer_prefix() -> str:
 
     If none of the above works, fall back to ``posix_prefix``.
     """
+    if _HAS_PREFERRED_SCHEME_API:
+        return sysconfig.get_preferred_scheme("prefix")
     os_framework_global = is_osx_framework() and not running_under_virtualenv()
     if os_framework_global and "osx_framework_library" in _AVAILABLE_SCHEMES:
         return "osx_framework_library"
@@ -57,6 +61,8 @@ def _infer_prefix() -> str:
 
 def _infer_user() -> str:
     """Try to find a user scheme for the current platform."""
+    if _HAS_PREFERRED_SCHEME_API:
+        return sysconfig.get_preferred_scheme("user")
     if is_osx_framework() and not running_under_virtualenv():
         suffixed = "osx_framework_user"
     else:
@@ -70,6 +76,8 @@ def _infer_user() -> str:
 
 def _infer_home() -> str:
     """Try to find a home for the current platform."""
+    if _HAS_PREFERRED_SCHEME_API:
+        return sysconfig.get_preferred_scheme("home")
     suffixed = f"{os.name}_home"
     if suffixed in _AVAILABLE_SCHEMES:
         return suffixed